Momentum over magnitude
With AI moving fast and reshaping how software gets built, you’d expect the developer skills landscape to be in full churn. But looking back at the full year of skills data from 2024, that’s not exactly what we see. At least, not on the surface.
The top five skills—SQL, REST API, Java, Python, and JavaScript—haven’t budged. But that’s not because nothing’s changing. It’s because their invite volume is so high that any shift would take something tectonic. Dig beneath these mainstays, though, and the story gets a lot more interesting.
To understand how skill demand is evolving, we looked at two key metrics from the HackerRank platform:
- Test Invites – How often candidates were invited to complete an assessment involving a given skill—a direct signal of hiring activity.
- Active Tests – The number of unique tests that included at least one invite for that skill during the year. This helps us spot broad demand, regardless of volume.
This year, we can also layer in a new signal: performance data from ASTRA, our benchmark for how well AI handles complex, multi-file coding challenges. When we overlay ASTRA results with our platform data, we’re able to see where AI progress is beginning to influence skill demand and hiring patterns.
This isn’t a leaderboard. It’s a readout of what’s moving, and what that movement tells us about how teams are adapting to a world with AI in the loop.
The mainstays continue to mainstay
The top five skills by invite volume haven’t shifted from last year. And they likely won’t anytime soon. The volume gap between these, and between them and the next tier, is massive. It would take a structural shift in how companies build software to knock any of them out of place.
Top 10 in-demand skills by invites (2024)
Top 5 skills by invite volume (2024)
| Rank (invites) | Skill | YoY growth (invites) | YoY growth (active tests) |
| 1 | SQL | 25.5% | 6.5% |
| 2 | REST API | 8.7% | -9.7% |
| 3 | Java | -4.7% | -7.7% |
| 4 | Python | 35.6% | 23.1% |
| 5 | JavaScript | 3.3 | -0.9% |
That said, within this dominant tier, there are signs of movement worth watching:
- SQL rebounded strongly (+26%) after a dip in 2023, likely tied to renewed investment in AI data infrastructure.
- REST API held flat for the second year in a row. It’s still a staple, but increasingly scaffolded by AI.
- Java dipped slightly in 2024 (-5%), and more notably, it’s the only one of the top skills still down compared to 2021—a 17% decline over three years. Its long-standing dominance may be starting to erode.
- Python continued its climb (+35%), strengthening its position as the language of AI, automation, and glue code.
- JavaScript remains flat as well: still everywhere, still essential, still impossible to dislodge.
These aren’t the most volatile skills, but they are the most embedded. Their dominance makes movement rare, but when it happens, it matters. For example, if Python keeps growing anywhere near its recent rate, there is a chance it could pass Java this year.
Momentum with real volume
Our next batch of standout skills isn’t competing with the Pythons and SQLs of the world in sheer volume, but they’re moving fast, and at scale. Most saw strong gains in both invites and active use, with several climbing the rankings. What ties many of them together is their role in building, connecting, and scaling complex systems; skills that sit closer to architecture than automation.
| Rank (invites) | Skill | YoY growth (invites) | YoY growth (active tests) | Rank change |
| 6 | C++ | 17% | 15% | +3 |
| 8 | System Design | 82% | 18% | +8 |
| 9 | C | 65% | -7.7% | +5 |
| 10 | React | 23% | 23.1% | +1 |
| 13 | Spring Boot | 75% | -0.9% | +4 |
| 19 | Docker | 106% | 34% | +7 |
| 25 | Kubernetes | 23% | 22% | +1 |
- System Design – Up 82% in invites and jumped from 16th to 8th: remarkable growth at meaningful scale. And it’s just growing quickly, it’s growing upmarket. System Design questions often involve high-context reasoning, tradeoff analysis, and architectural thinking across domains. These are the kinds of challenges AI still struggles with, and that may be exactly why demand is rising.
- C++ – A legacy language with modern momentum. Up 17% in invites this year, and 71% since 2021. It also climbed from 9th to 6th in invite rank. This kind of sustained growth in an older language raises questions: Is it about embedded systems? Edge compute? AI infrastructure?
- C – followed a similar trajectory, up six spots in invite ranking, with major year-over-year growth. It powers firmware, operating systems, and resource-constrained environments where efficiency beats abstraction. Together with C++, it might be worth asking: Why are low-level languages booming now?
- React – Up 23% after a slight dip in 2023. It remains the dominant front-end framework—and by far the skill most front-end developers say they’re focused on for 2025. But AI is catching up quickly here: ASTRA shows models correctly solve React-based challenges about 87% of the time. Hiring demand hasn’t dipped yet, but it’s a space to watch closely.
- Spring Boot – This framework has quietly become one of the most stable and widespread back-end stacks in enterprise hiring. It’s also the main skill back-end developers say they’re focused on this year. While AI is starting to make headway (ASTRA benchmark: 0.470), human orchestration continues to be mission critical, especially when stitching together real-world services and systems.
- Kubernetes – posted healthy growth across both metrics. But Docker, often mentioned in the same breath, grew even faster—more than doubling in invites. As companies lean further into containerized, cloud-native systems, both skills are surging.
These skills reflect the kind of engineering that still benefits most from human context, judgment, and design—and they’re in high demand for a reason.
Why are C and C++ booming?
C and C++ are among the oldest languages in tech and two of the fastest risers this year. What’s that about?
Their resurgence comes down to low-level control meeting high-stakes systems. Both languages are used in:
- Embedded systems – powering everything from automotive ECUs and industrial robots to medical infusion pumps and smart home devices.
- Edge computing – where code needs to run on-device, like in drone navigation, autonomous vehicles, or voice assistants operating offline.
- Operating systems and runtimes – from Linux kernel development to the memory management layers behind mobile operating systems and databases.
- AI infrastructure – including GPU programming (CUDA), model-serving frameworks, and optimized inference runtimes used in high-performance deployments.
But it’s not just about new applications. In many industries, they’re still the backbone of large, complex legacy systems that now need to connect with AI.
These aren’t throwback skills. They’re the connective tissue between new and old, cloud and edge, high-level logic and hardware-aware execution. And in 2024, that makes them more relevant than ever.
What ASTRA tells us (so far)
Our ASTRA benchmark measures how well various AI models handle complex, multi-file coding challenges across specific skills. In other words, it offers a granular look at where AI is progressing across the software development lifecycle, and where it still has a ways to go.
Over time, ASTRA scores could help surface early signals—and even forecast patterns—in hiring behavior. But for now, the correlation between AI performance and skill demand is limited and inconsistent.
In some cases, there’s an early suggestion of alignment. Ruby (ASTRA 0.700) and Django (ASTRA 0.870) both show strong AI performance and notable declines in both invites and active test usage. That could signal early automation, or simply waning relevance for those stacks overall.
Other skills complicate the picture. Angular and Spring Boot both have relatively high ASTRA scores but continue to see healthy growth. Their roles in complex, enterprise-scale systems may sustain demand even as AI improves.
As of late March 2025, ASTRA benchmarks don’t yet display a statistically relevant correlation to developer skill demand. But it’s a signal worth watching, especially as AI capabilities continue to expand across a broader range of tasks.
What this means for teams and developers
For hiring managers:
- Look beyond the leaderboard. The top five skills may not have moved, but real change is happening below the surface. Momentum matters.
- Pay attention to system-level and infrastructure-adjacent skills. They’re seeing consistent growth and anchoring how modern software gets built.
- Keep an eye on automation-prone areas. ASTRA doesn’t show strong correlation yet, but as it matures, it may help highlight where human skills are becoming less differentiated.
For developers:
- Don’t just learn tools—learn systems. The fastest-growing skills often live closer to architecture, orchestration, and integration.
- Follow the momentum. Skills like Python, SQL, System Design, and Spring Boot offer both staying power and strategic relevance.
- Track AI’s progress, but don’t panic. Skills that pair well with AI (or sit above it in abstraction) will only become more valuable.
Why momentum matters most
The leaderboard didn’t shift in 2024, but it’s not the real story. Skills like System Design, C++, and Spring Boot didn’t just grow; they gained real ground in real hiring workflows.
In an AI-influenced landscape, it’s easy to focus on what’s being replaced. But it’s just as important to focus on what’s becoming more essential. Skills that help teams reason, connect, and build at scale are the ones showing up again and again in the data.
In a year shaped by AI, the strongest skills signals pointed back to human judgment, foundational tools, and the systems that hold everything together.