Why Zalando’s tech radar sucks as a stack


I’ve been programming professionally for about 5 years now. So I don’t consider myself a brilliant expert.

Never the less one thing I think that I’ve learned is that it isn’t about the ‘technical problems’ it’s about whether or not you solve a real-world or meaningful problem.

Some people call these ‘business problems’ but they could apply equally in academia/ not-for-profit worlds.

Another thing I’ve learned is that choosing new technology has costs, there are always tradeoffs.

Some of my thinking on this is formed by choose boring technology

It’s good to discuss the social and operational cost of a new technology. I’ve learned for instance that although kubernetes can be a great tool – there is a cost to training developers in it. This cost is non-trivial. And we as technological leaders should be careful when we bring these things in.

I think if you don’t carefully manage technological choices you can end up with something like Zalando’s radar, and while it’s good to have that – you don’t want that to be your entire stack.




How do we deliver Data Science in the Enterprise


I’ve worked on Data Science projects and delivered Machine Learning models both in production code and more research type work at a few companies now. Some of these companies were around the Seed stage/ Series A stage and some are established companies listed on stock exchanges. The aim of this article is to simply share what I’ve learned — I don’t think I know everything. I think my audience consists of both managers and technical specialists who’ve just started working in the corporate world — perhaps after some years in Academia or in a Startup. My aim is to simply articulate some of the problems, and propose some solutions — and highlight the importance of culture in enabling data science.

I’ve been reflecting over the years as a practitioner why some of this ‘big data’ stuff is hard to do. I’ll present in this article a take that’s similar to some other commentary on the internet, so this won’t be unusual.

My views are inspired by http://mattturck.com/2016/02/01/big-data-landscape/ in this article Matt says:

Big Data success is not about implementing one piece of technology (like Hadoop or anything else), but instead requires putting together an assembly line of technologies, people and processes. You need to capture data, store data, clean data, query data, analyse data, visualise data. Some of this will be done by products, and some of it will be done by humans. Everything needs to be integrated seamlessly. Ultimately, for all of this to work, the entire company, starting from senior management, needs to commit to building a data-driven culture, where Big Data is not “a” thing, but “the” thing.

Often while speaking about our nascent profession with friends working in other companies we speak about ‘change management’. Change is very hard — particularly for established and non-digital native companies, companies who don’t produce e-commerce websites, social networks or search engines. These companies often have legacy infrastructure and don’t necessarily have technical product managers nor technical cultures. Also for them traditional Business Intelligence systems work quite well — reporting is done correctly, and it’s hard to make a case for machine learning in risk-averse environments like that.

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One weird tip to improve the success of Data Science projects


I was recently speaking to some data science friends on Slack, and we were discussing projects and war stories. Something that came across was that ‘data science’ projects aren’t always successful.


Source: pixabay

Somewhere around this discussion a lightbulb went off in my head about some of the problems we have with embarking on data science projects. There’s a certain amount of Cargo cult Data Science and so collectively we as a community – of business people, technologists and executives don’t think deeply enough about the risks and opportunities of projects.

So I had my lightbulb moment and now I share it with everyone.

The one weird trick is to write down risks before embarking on a project.

Here’s some questions you should ask you start a project – preferably gather all data .

  • What happens if we don’t do this project? What is the worse case scenario?
  • What legal, ethical or reputational risks are there involved if we successfully deliver results with this project?
  • What engineering risks are there in the project? Is it possible this could turn into a 2 year engineering project as opposed to a quick win?
  • What data risks are there? What kinds of data do we have, and what are we not sure we have? What risks are there in terms of privacy and legal/ ethics?

I’ve found that gathering stakeholders around helps a lot with this, you hear different perspectives and it can help you figure out what the key risks in your project are. I’ve found for instance in the past that ‘lack of data’ killed certain projects. It’s good to clarify that before you spend 3 months on a project.

Try this out and let me know how it works for you! Share your stories with me at myfullname[at]google[dot]com.



Avoiding being a ‘trophy’ data scientist


Recently I’ve been speaking to a number of data scientists about the challenges of adding value to companies. This isn’t an argument that data science doesn’t have positive ROI, but that there needs to be an understanding of the ‘team sport’ and organisational maturity to take advantage of these skills.


Trophies are nice to look at but they don’t drive business decisions.

The biggest anti-pattern I’ve experienced personally as an individual contributor has been a lack of ‘leadership’ for data science. I’ve seen organisations without the budgetary support, the right champions or clear alignment of data science with their organisational goals. These are some of the anti-patterns I’ve seen, it’s non-exhaustive so I provide it.

The follow is an opinionated list of some of the anti-patterns.

  • I’ve written before about data strategy. I still think this is one of the things that’s most lacking in organisations. I think a welcome distinction is that data collection which needs to happen before data analysis, and that this needs to happen in accordance with the strategy of the company.

Solution: Organisations should map their data science projects to the key business concerns of the organisation. This will help shape how resources are allocated.

  • There needs to be an understanding of what kind of leadership you need for a data science team. This needs to be someone with hands-on experience of doing data science. This is not someone familiar with ‘analytics’ or ‘reporting systems’ and ‘delivery’. It is someone familiar with things like ‘probabilistic programming’, ‘neural networks’ and ‘A/B tests’. So don’t put an ‘analytics leader’ in charge of a team of data scientists.

Solution: Executives – feel free to reach out to me to discuss data strategy, I’ll gladly point you in the right direction.

  • You need Business intelligence not data science – there’s nothing wrong with reporting, or building analytics systems, but it’s not data science. Be honest about what your organisation needs.

Solution: Ask clarifying questions when interviewing about why the organisation needs data science versus other things.

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Interview with a Data Scientist – Ian Wong of OpenDoor

I interviewed the interesting and fascinating Ian Wong – he’s the technical co-founder of OpenDoor, which I personally think is amazing as a concept!
(Ian Wong – Source: Linkedin)
1. What project have you worked on do you wish you could go back to, and do better?
Pretty much any project I’ve worked on in the past smiling face with open mouth Two projects stick out though.
a. Uniform API for Data Fetching
When we fit a model, call it y = f(X),  (X, y) are often taken for granted to be well-formed. How do you design a service that generates consistent (X, y)? Turns out this is not straightforward, and is specific to the domain and the data-capture systems.
The ideal solution would satisfy both batch & real-time needs; makes it easy to ship new features to production; and enables rapid prototyping. While I scrapped together the initial version at Opendoor, our amazing team of data engineers have really taken it to the next level. We hope to report our findings soon.
b. Interactive Visualizations of ML Algorithms
A few years ago, I tried putting together a visualizer for random forests using d3. I had the tremendous fortune of working with Mike Bostock for a bit, and was inspired by his ability to make abstract concepts tangible through interactive visualizations. At the time, I was working with these big sets of random forests, and wanted a get a better feel of the model outputs. So I rendered hundreds of decisions trees on screen, where when you hovered over one node, all other nodes belonging to the same features across different trees would be highlighted. It was pretty neat! But the prototype suffered from performance issues plus my own technical incompetence.
More broadly, I’m really excited about better interactive tools for ML algorithms because they’ll help us deeply understand them as tools. During my undergrad studies in electrical engineering, we used to play with circuits a lot. In the labs, you could make a change to the input or to the circuitry, and see the corresponding change in output on the oscilloscope instantaneously. When we run a simple regression, wouldn’t it be great to get immediate feedback on the fitted line if we were to drag, add, delete a data point?
I’m hopeful we’ll see more innovation in the read-eval-print loop for data science.
2. What advice do you have to younger analytics professionals and in particular PhD students in the Sciences?
My view may be slightly biased as I’m a PhD drop-out winking face In grad school, I became increasingly frustrated at the divergence between what’s interesting and what’s impactful. But that’s a whole separate conversation.
For folks looking to enter industry, nothing replaces hands-on practice. I would strongly encourage students to look for internships, participate in Kaggle competitions / Google Summer of Code, seek open source projects to contribute to. If you’re in school, take a wide variety of classes, especially computer science and project-based courses.
The higher order bit here is that the industry faces a different, evolving set of challenges than academia. The focus is typically on solving a business problem.
Here are additional pointers depending on the reader’s interest.
Business Analytics & Decision Science
  • The grammar of graphics and tidydata lay a great foundation for reasoning about data. I personally learned more by working through Hadley’s ggplot2 book than from many of my stats classes at Stanford. 
  • Develop business acumen and communication skills. Sometimes academics prefer to stay in the rarified air of theory and mathematics. Success in the analytics profession requires the ability to (a) meet hard business challenges head on, (b) break them down into smaller, quantifiable sub-problems, (c) rapid analysis, (d) present findings in a way that the audience can engage with, (e) take feedback and iterate.
Machine Learning & Engineering
  • Code, code, code. As I mentioned in Doing Data Science: ML is founded in math, expressed in code, and assembled into software. Being able to build robust software systems is becoming more important, as tools and algorithms are increasingly available.
  • While a strong grasp of theory will help narrow design choices, nothing beats rapidly exploring hypotheses. This demands coding proficiency, which from experience is a differentiating trait of highly productive data scientists.
Also, don’t let your field tie you down! Beware of sunk cost fallacy. Though PhDs may have invested years studying a certain field, the techniques investigated through a graduate program may not be transferable to a new domain. The most important quality of the PhD is persistence in doing research. Remember, it’s re-search search and search again. That’s what defines a great problem solver.
3. What do you wish you knew earlier about being a data scientist?
There are so many! Here’s a few.
How to build great predictive services
While we spend a lot of energy in grad school studying techniques, advanced techniques often yield only incremental lift over a simple solution (and in many cases comes with complexity that becomes a heavy tax). I think the big focus on modeling techniques contributes to the phenomenon of solutions chasing problems, rather than solutions being designed from the needs of the problem. Here’s a rule of thumb that I’ve come to adopt: You know that algorithm that all the papers make fun of in their intro? Implement that and forget the rest of the paper.”
Perhaps influenced by schooling, we as data scientists often dream about having these flashes of brilliance that identifies a proof! QED! In practice, what delivers results is an error-focused, iterative process of continuous model improvement (see my talk here). It’s the unglamorous engineering & detective work of starting with the biggest outliers of the model, and reasoning from first principles to eliminate them. Model debugger describes the role better than data scientist. It’s about the toil.
Forming a perspective based on incomplete data
Intellectual honesty, scientific doubt and a healthy dose of paranoia are generally great things to have. But beware of analysis-paralysis and failure to put a stake in the ground. Decisions need to be made in a timely fashion. In many cases we’re operating with 80% information (if lucky!), and your teammates are counting on you for a recommendation.
Earlier in my career, I would be reluctant in forming and articulating a strong perspective. Partly due to skepticism inculcated through school, and partly because it didn’t seem like it was my job as a data scientist to do so (more on titles being a constraint later). Making an actual policy recommendation seems so messy relative to the clean code and beautiful plots staring at me on the monitor. But I’ve since learned that this is an abdication of responsibility. Our job is to help the company make data-driven decisions, which means thinking through the implications of an analysis, consulting stakeholders, and coming up with a point of view.
Communication as craft
The value of an analysis is measured by whether it influences decisions. Even the most brilliant analysis becomes ineffective if not delivered to the audience in an accessible manner. This Jeff Atwood blog post explains the concept well.
Other things!
There are many other things I wish I knew earlier. How do I pick up software engineering skills? What does a great data scientist look like? How do I progress to become better? How do I foster effective debate and engagement of my work? I’ll omit them for now since this is getting long…
4. How do you respond when you hear the phrase big data’? What about AI’?
On Big Data
There’s big data, and there’s Big Data. If you’re referring to the latter, I think it’s a bit passé at this point (with some exceptions).
Turns out that more data beats better algorithms most of the time. As an industry we have worked really hard to make count(x) group by y scale to terabytes of data. But as alluded to earlier, the tools and infrastructure are increasingly commoditized. We’re ready to move onto higher parts of the application stack vs. focusing on the base layer. (e.g., Opendoor! See also the vertical AI piece by Bradford Cross.)
Turns out machines are tireless and can count much more reliably than human beings. This has implications as we enter the age of abundant data. This can get philosophical quick! But there are both benefits and hazards we’ll need to navigate.
5. What is the most exciting thing about your field?
As technology and education improves and become more accessible, there’ll be an increased supply of data science and machine learning talent. These individuals will become the next generation builders and leaders. Algorithmic sophistication is going to seep into all parts of our daily lives. The products they create are going to be smarter, easier to use and more personal (Opendoor being an example smiling face with open mouth).
6. How do you go about framing a data problem in particular, how do you avoid spending too long, how do you manage expectations etc. How do you know what is good enough? 
As Alan Kay once said: A change in perspective is worth 80 IQ points. Framing a problem well is probably the most important part of the solution.
Within the context of building predictive services, defining the objective function with a clear metric that’s ideally back-testable is half the battle. It provides a foundation for the rest of the work, which entails applying the simplest approach, iterating until convergence to some threshold that’s set by business needs. The art comes in how to define the ML problem in a way that aligns with business outcome (ideally tracing all the way through to the top- or bottom-line).
In terms of when is good enough, that depends on the need. Running a company is kind of like trying to solve an NP-hard resource optimization problem. We have to be rigorous about ROI for each initiative that we spend energy on.
In terms of managing expectation, it’s hard. It folds into longer term project and team planning. What is the business problem we’re trying to solve? What does success mean? Where do we need to be today, a quarter from now, a year from now? Who are the stakeholders? How should we provide updates and receive feedback?
7. You’ve spoken about people not needing to be constrained by titles. Could you expand a bit on that? What sort of skills should someone with ML skills be learning in your opinion? What have you learned working at Opendoor?
On Being Boxed in by Titles and Venn Diagrams
Titles should enable, not constrain. We are all problem solvers first. A title acknowledges that an individual is skilled in a certain area. But one shouldn’t let that define their boundaries. When misused, titles could be a escape hatch to avoid doing the things that matter. For instance, a misinformed data scientist may think of productionizing their insight” as unnecessary implementation detail, while a misinformed software engineer may think of defining data quality SLA for predictive systems as esoteric. In practice, there’s a metric to move, a question to be answered. Titles endow neither immunity nor magical problem-solving powers. What matters is clarifying the job to be done.
In a PhD program, there’s a tendency to put blinders on and focus on one problem, specified by one professor in one department. In industry, solutions tend to be multi-disciplinary. A lot of what we do as data scientists is to take human intuition and generalize them, seeing which withstand the backtest or an experiment. And to do this well, we need to be open to new ideas and continuously develop new skills. As allude to earlier, some of the key ones are (a) business intelligence and (b) software engineering (including frontend!).
But I would be remiss not to mention the following
  • Scrappy + Pragmatic + Business Acumen > Technical Expertise
The best data scientists are relentlessly resourceful and impact- / solution-oriented. Mindset shifts from I need to gain skill x” to I am going to solve problem y”; from not my job” to run towards where the impact is.”
It’s been an incredible journey thus far at Opendoor. We are on a mission to empower everyone with the freedom to move by building a seamless, end-to-end customer experience that makes buying and selling a home stress-free and instant. The experience of growing our team, scaling up as a leader and servicing thousands of customers has been really rewarding. It’s the perfect blend of crazy-hard technical challenges and creating positive impact in people’s lives.
We’re only getting started! If any of this seems exciting, check out http://opendoor.com/jobs, or email me at ian@opendoor.com.
These are great questions and I had a fun time (partially) answering them!
Ian is working on modernizing the residential real-estate industry. He is the technical co-founder of Opendoor, where he leads their engineering and data science team. He previously built fraud detection systems at Square as their first data scientist, and products at Prismatic. Ian received his BS in EE (Electrical Engineering), MS in EE and MS in Statistics from Stanford before dropping out of the PhD.

Working in a major trend – Machine Learning


I saw recently this from the recent Amazon shareholder letter.

“These big trends are not that hard to spot…We’re in the middle of an obvious one right now: machine learning & artificial intelligence” — Jeff Bezos

One of the hard parts about working professionally on these technologies. Is I take them for granted. So I consider this a post to just reflect on the improvements in image processing, computer vision, translation, natural language processing, text understanding, forecasting, risk analysis.

I’ve worked on some of these technologies, and these challenges, and continue to work on extracting information from CVs and matching candidates to the best jobs for them at Elevate Direct. When you’re in the weeds you sometimes forget what you’re working on, and that you’re part of a major trend.

As Matt Turck says

Big Data provides the pipes, and AI provides the smarts.

AI in the Enterprise (the problem)


I was recently chatting to a friend who works as a Data Science consultant in the London Area – and a topic dear to my heart came up. How to successfully do ‘AI’ (or Data Science) in the enterprise. Now I work for an Enterprise SaaS company in the recruitment space, so I’ve got a certain amount of professional interest in doing this successfully.

My aim in this essay is to outline what the problem is, and provide some solutions.

Firstly it’s worth reflecting on the changes we’ve seen in Consumer apps – Spotify, Google, Amazon, etc – all of these apps have personalised experiences which are enhanced by machine learning techniques depending on the labelled data that consumers provide.

I’ll quote what Daniel Tuckelang (formerly of Linkedin) said about the challenges of doing this in the enterprise.

First, most enterprise data still lives in silos, whereas the intelligence comes from joining across data sets. Second, the enterprise suffers from weak signals — there’s little in the way of the labels or behavioral data that consumer application developers take for granted. Third, there’s an incentive problem: everyone promotes data reuse and knowledge sharing, but most organizations don’t reward it

I’ve personally seen this when working with enterprises, and being a consultant. The data is often very noisy, and while there are techniques to overcome that such as ‘distant supervision‘ it does make things harder than say building Ad-Tech models in the consumer space or customer churn models. Where the problem is more explicitly solvable by supervised techniques.

In my experience and the experience of others. Enterprises are much more likely to try buy in off-the-shelf solutions, but (to be sweepingly general) they still don’t have the expertise to understand/validate/train the models.There are often individuals in small teams here & there who’ve self-taught or done some formal education, but they’re not supported. (My friend Martin Goodson highlights this here)  There needs to be a cultural shift. At a startup you might have a CTO who’s willing to trust a bunch of relatively young data science chaps to try figure out an ML-based solution that does something useful for the company without breaking anything. And it’s also worth highlighting that there’s a difference in risk aversion between enterprises (with established practices  etc) and the more exploratory or R and D mindset of a startup.

The somewhat more experienced of us these days tend to have a reasonable idea of what can be done, what’s feasible, and furthermore how to convince the CEO that it’s doing something useful for his valuation.

Startups are far more willing to give things a go, there’s an existential threat. And not to forget that often Venture Capitalists and the assorted machinery expect Artificial Intelligence, and this is encouraged.

Increasingly I speculate that established companies now outsource their R and D to startups, hence the recent acquisitions like the one by GE Digital.

So I see roughly speaking two solutions to this problem. Two ways to de-risk data science projects in the enterprise.

1) Build it as an internal consultancy with two goals: identifying problems which can be solved with data solutions, and exposing other departments to new cultural thinking & approaches. I know of one large retailer who implemented this by doing 13 week agile projects, they’d do a consultation, then choose one team to build a solution for.

2) Start putting staff through training schemes similar to what is offered by General Assembly (there are others), but do it whole teams at a time, the culture of code review and programmatic analysis has to come back and be implemented at work. Similarly, give the team managers additional training in agile project management etc.

The first can have varied success – you need the right problems, and the right internal customers – and the second I’ve never seen implemented.

I’d love to hear some of the solutions you have seen. I’d be glad to chat about this.

Acknowledgements: I’d like to thank the following people for their conversations: John Sandall, Martin Goodson, Eddie Bell, Ian Ozsvald, Mick Delaney and I’m sorry about anyone else I’ve forgotten.