Top programming languages and topics: Here’s what developers want to learn about

O’Reilly Media analysed data on its learning platform’s 2.8 million users to find out what developers were keen to learn in 2022 — and, not surprisingly, AI was the biggest topic of interest. 

Content about natural language processing (NLP) saw a spike in growth of 42% year on year, while the underlying category of deep learning was the second-most heavily used topic, with 23% growth, according to O’Reilly’s Technology Trends for 2023 report. 

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O’Reilly’s snapshot of trends in learning is based on its internal “units viewed” metric, which is a measure of how many times IT workers and developers view ebooks, videos and live training courses about key subject areas.   

While some topics boomed, others slowed: interest in reinforcement learning declined 14%, while content about chatbots declined 5.8%. 

Mike Loukides, vice president of emerging technology content at O’Reilly, notes the decline in views about chatbot learning modules “seems counterintuitive” but makes sense in hindsight, given interest in OpenAI’s ChatGPT and GPT-3 and -3.5 large language models. 

“The release of GPT-3 was a watershed event, an “everything you’ve done so far is out-of-date” moment,” writes Loukides. “We’re excited about what will happen in 2023, though the results will depend a lot on how ChatGPT and its relatives are commercialized, as Microsoft moves toward offering ChatGPT as a cloud-based service.”

O’Reilly’s popularity rankings of programming languages showed a few surprises. Java and Python were the leaders by a long way and saw minor gains, while interest in Rust and Go grew 20% each. Go was the third most popular language, followed by C++, JavaScript, C#, C, Rust, Microsoft’s JavaScript superset TypeScript, R, Kotlin, and Scala. This order is quite different to RedMonk and Tiobe’s rankings.  

In terms of infrastructure and operations material, containers, Linux and Kubernetes were the top topics. Containers saw 2.5% growth, while Linux and Kubernetes saw 4.4% growth each over the year. Content about service mesh, a part of the Kubernetes ecosystem, saw a 28% decline, while content about Istio — the service mesh implementation most closely tied to Kubernetes — declined 42%. 

The top subjects behind containers, Linux and Kubernetes were DevOps, Docker, Terraform, Ansible, site reliability engineering, Puppet, service mesh, and Istio. 

Interest in Terraform, the “infrastructure as code” tool by HashiCorp, saw a major increase of 74%. “Terraform’s goals are relatively simple: You write a simple description of what infrastructure you want and how you want that infrastructure configured. Terraform gathers the resources and configures them for you,” explains Loukides. 

Interest in learning about specific cloud players was dominated by Amazon Web Services, followed by Microsoft Azure, Google Cloud, Oracle Cloud, and IBM Cloud. 

While the big three dominated, they all decreased in year-over-year usage: AWS was down 3.8%, Azure 7.5%, and Google Cloud 2.1%. 

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O’Really doesn’t know what caused the decline. However, Loukides points to one potential suspect that’s more talked about these days: public cloud repatriation, where companies bring their cloud-hosted applications in-house. 

“Cost is the greatest motivation for repatriation; companies moving to the cloud have often underestimated the costs, partly because they haven’t succeeded in using the cloud effectively,” he writes. 

“While repatriation is no doubt responsible for some of the decline, it’s at most a small part of the story. Cloud providers make it difficult to leave, which ironically might drive more content usage as IT staff try to figure out how to get their data back. A bigger issue might be companies that are putting cloud plans on hold because they hear of repatriation or that are postponing large IT projects because they fear a recession.”