2025 Recap: The Year Software Development Changed Shape

投稿日 12月 20, 2025

2025 was the year software teams stopped optimizing models and started optimizing systems.

By December, a few truths were impossible to ignore.

1. Developer Productivity Became the Real Competitive Advantage

By mid-year, every major AI lab had cleared the “good enough reasoning” bar. With model quality converging, the differentiator was no longer raw intelligence. It was how fast teams could ship.

The fastest teams used systems that were:

  • Declarative: automation defined in YAML and config, not code
  • Composable: agents calling tools with minimal glue
  • Observable: evaluated, traced, and versioned 
  • Reproducible: identical behavior every run

Productivity became a platform problem, not a talent problem.

2. Security Went From “Filters” to “Blast Radius”

The real problem wasn’t what models say. It was what they could do.

Once agents can act, blast radius matters more than the prompt.

Production incidents across the industry made it clear:

  • Agents leaking internal data within minutes
  • Malicious plugins shipping ransomware
  • Supply-chain bugs in AI tooling 
  • Agents deleting repos or months of work

Smart teams adopted the same guardrails they use for privileged system processes:

  • Sandboxed runtimes
  • Containerized toolchains
  • Signed artifacts
  • Policies in front of tool calls
  • Hardened bases and reproducible builds

The industry stopped filtering danger out of the model. They focused on containing it.

3. Agents Stopped Being Demos 

Agents became good enough to do real jobs.

At the start of the year, “agent” meant a clever prototype. By the end, agents were doing operational work: updating infrastructure, resolving customer issues, moving money, managing SaaS tools.

Two shifts unlocked this:

  • Reasoning took a leap.
    OpenAI’s o3 solved 25% of FrontierMath, problems that take researchers hours or days. DeepSeek sent waves with their R1 model, proving that the frontier moved from model size to compute at inference time.
  • Tools became standardized.
    MCP became the USB-C port of AI, a universal way for agents to safely access tools, data, and workflows. Once the ecosystem aligned on a common port, everything accelerated.

4. Containers Quietly Remained the Execution Layer for Everything

Containers continued doing the quiet work of powering every stack.

More than 90% of companies used containers as the default environment where:

  • Applications run
  • Build systems operate
  • Agents execute real tasks
  • Infrastructure is tested before hitting production

Even in an agent-driven world, developers need environments that act the same way every time. Containers remained a universal, stable execution surface.

5. Hardened Images Became the New Starting Point

You can’t trust the system if you don’t trust the base image. 

Docker Hardened Images (DHI) solved the first question every team had to ask: “What are we actually running?” 

DHI answered that with:

  • A known, verified base image
  • A transparent bill of materials
  • Reproducible builds
  • Signed artifacts

When hardened images became free, the cost of doing the right thing dropped to zero. Teams no longer layered security patches on top of unknown upstream risk. They began from a secure, trusted baseline.

What’s Next for 2026

The race for raw model intelligence is over. What separates winners in 2026 will be everything around the model.

  1. Agents become a standard runtime target. Versioned and deployed like services.
  2. Security frameworks treat agents as users. With permissions, onboarding, and monitoring.
  3. Ecosystem gravity increases. MCP is the start. The dominant tool interface becomes the center of the agent economy.
  4. Trust becomes infrastructure. Signed models to verified tools to hardened bases. Winners will have the smallest blast radius when things break.
  5. The term “AI engineer” fades. What remains is what has always been: software engineers who build secure, governable, and resilient systems.

In 2023, we learned to talk to models. In 2024, we learned to chain them. In 2025, we gave them real power.

2026 will be about earning the right to keep it.

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