Retrospective: Software Engineering Summer Internship (2015) at Jeppesen Systems AB in Gothenburg

Introduction

Jeppesen is a fully owned subsidiary of Boeing, and part of their Digital Aviation business. Concretely, they provide navigational information, crew and fleet management solutions, and offer an industry-leading optimization product. The Gothenburg office started originally as Carmen Systems, which was spun off Chalmers University of Technology. Ties between Chalmers and Jeppesen are still strong. The Gothenburg office of Jeppesen employs around 350 people, of which around 300 are technical staff. Further, there are around 60 contractors in the building.

Jeppesen was not an entirely new entity to me. I had been mentored by one of their managers for about a year, though whom I met several other Jeppesen employees, including a veteran software architect with a very strong technical background, and an experienced software developer. Further, I was one of the winners of a coding competition they held this spring, and one of five students who were invited to what turned out to be an intimate recruiting event, where we were outnumbered by Jeppesen managers and employees. Several managers represented their division, the challenges they are working on, and, of course, the kind of skills they are looking for in future employees. Alas, back then they did not have any openings, but we were told that a number of full-time positions would open up in autumn, and possibly some summer internships as well. Both turned out to be the case.

The interview

I applied for a data processing project with a parallel programming component, which I will detail further below. But before I got to do any work, I had to make it through the interview. Job interviews are often cringe-worthy, particularly the “your greatest weakness”-kind. The interview experience at Jeppesen was distinctly positive, though. The hiring manager briefly came in to shake hands and exchange some niceties, but otherwise, the interview was conducted by two senior engineers. They described the project, how they work, and the technologies they use.

What I greatly appreciated was that they were looking for competence instead of buzzwords. We even talked a bit about the necessary computer science background for their project. It was helpful that I had heard of recursive descent parsing, had written a parser for a subset of C++, or implemented a compiler for a C-like language. Normally, a coding test is also part of the interview process, but I presume this was skipped due to my performance on their recent coding challenge. Still, they asked me a few ‘design’ questions, like how I would approach this or that problem, or pros and cons of concrete approaches to given problems. Thankfully, it was more about how to break down a complex task into manageable subproblems, instead of the dreaded UML and design patterns interview.

The project

Of course I signed and NDA can therefore not be too specific, so I am only going to describe the problem in general terms. Let’s say your software runs on dozens or possibly even hundreds of machines at a customer site. Each copy of the program produces partly unstructured log files, recording all kinds of things. In order to extract useful information from those log files, you have to run a parser that understands the structure of the files, and extracts relevant information, which may be processed further. To make this even more fun, let the client machines run around the clock, and update log files continually. This sounds fairly complicated already. However, keep in mind that you have more than one customer, many more than one parser, and currently you only execute one parser after another in a sequential order via a cron job once a day, for historical reasons, maybe because the programs predate the many-core CPU era.

The goal of the project I was given was to write a framework that parses all log files — think in orders of magnitudes of tens of thousands of files — in pseudo-real time, so that you can extract more useful information from the existing data. For instance, if you take a metric like ‘active instances’ once a day, you’ll learn a lot less than if you are able to update this metric every few minutes.

Concretely, the framework I developed unified the existing parsers for several Jeppesen products. Understanding and modifying existing parsers required a little bit of background in programming languages. This was pretty fun, but the most interesting aspect was trying to find ways to effectively parallelize the execution of the parsers. The hardware at our disposal was pretty decent. Thus, running a single-threaded program on a many-core CPU is a bit of a waste, to put it mildly. My approach was to avoid all shared state. Once this problem was solved, the actual parallelization was easy to achieve. The machine I was mostly working on was an Intel Xeon with 16 cores and over 100 GB RAM, which was far from being the most powerful machine I had access to. Even on that one, we easily hit our performance target.

In my last two weeks, I had plenty of time to ensure the documentation was comprehensive. At the same time, my main supervisor put the project successfully into production at two customer sites, both major European airlines. At both sites we encountered minimal issues that were easily resolved. In one case, the volume was much greater than the fairly large test data directory I had been working with, so I needed to use a more efficient data structure, and make use of memoization at one point in order to resolve a bottleneck. At the other customer site, a slightly different naming convention for some files was used, which was an even easier fix. My last update was that this product has been successfully rolled out to two more customers.

The software development process

While Jeppesen is officially committed to “Agile”, they nonetheless have a strong engineering culture, which entails that they make use of software processes not for their own sake but when there is a clear benefit. The first few days on the job, I was expected to do the daily “stand up” song and dance, and report on everything I’ve done, what I intended to do that day, and give various estimates about the next few days. Personally, I found this more annoying than helpful. After I showed a proof of concept of this product after a few days, instead of the planned two weeks, my supervisors concluded that I can apparently work well on my own, and scrapped daily meetings. Instead, we had the occasional demo session, or just casually discussed progress during company breakfast.

I did like that, after proving myself, I was given relatively free reign with regards to the development, of course while still conforming to the overall vision of the product, which I received at the beginning in the form of a succinct document. The eventual software development process was somewhat reminiscent of Iterative and incremental development.

The work environemnt

Based on my experience at a previous employer, and from various company visits, I would say that Jeppesen has a clearly above average office environment. It’s not uncommon that three or four employees share their own, reasonably spacious office. However, there are also several open-plan office areas, the kind that is claimed to foster cooperation and communication, even though they are “damaging to the workers’ attention spans, productivity, creative thinking, and satisfaction”. Well, Joe Programmer, no matter where on the world he works, sadly does not command enough status to get his own office. Thus, companies are, quite literally, squandering money by not giving people access to (genuinely) quiet working environments.

Still, thanks to artificial dividers, plants, and a reasonable amount of space, the open-space areas at Jeppesen are quite okay. I was sitting in one of the larger ones in the building, among around 15 employees, all fairly well spread-out. The main office hours are a bit busy, with infrequent distractions. However, if you come in very early or stay late, you can enjoy a quiet working environment and get a lot done. During the busier hours of the day, you may notice decreased productivity, compared to, say, intently working on something in the privacy of your home.

A few perks are offered, too. Every morning, there is free basic breakfast, which is also a great opportunity to talk to people outside of your department. Further, bowls of fruit are placed all over the building. This being Sweden, there is also a strong tradition of having ‘fika’, i.e. a short break for consuming coffee and pastries. Noteworthy is that a masseuse visits the office in regular intervals, for which you can sign up at reception, and get the cost deducted from your pay. Regular employees are even entitled to some free money (friskvård) for that purpose, or other health-related expenditures.

Working hours are quite flexible. You are expected to put in 40 hours per week. As a rank-and-file employee you have to be present during core business hours (9:00 to 15:00), but you do have some flexibility otherwise. For instance, taking the occasional long lunch break, and staying longer some other days is certainly something you can discuss with your manager, just like taking half a day off and putting in a few more hours on some other days to make up for it. Overall, they try to achieve a good work/life balance.

Summary

This was a very enjoyable internship, and a summer well-spent. The end result was that I wrote, relatively independently, a medium-sized application weighing in at thousands of lines of code, all tested and well-documented. It was a good mixture of intellectual challenge and more mundane practical aspects. In the beginning, intellectual challenges were more dominant, like the entire design of the product, or figuring out effective parallelization. Later on, the focus was much more on polishing the code base, and eventually deploying it. The latter was not quite as mentally stimulating, but on the other hand it was immensely gratifying to see the project hitting or exceeding all performance targets, as well as its successful deployment.

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