Why Your Org Should Standardize on TypeScript for Serverless (and Keep Java in Reserve

Why Your Org Should Standardize on TypeScript for Serverless (and Keep Java in Reserve)

If you’re leading a technology organization today, you’re probably being pulled between competing languages, frameworks, and cloud patterns. When it comes to serverless development on AWS, the tension often comes down to a familiar choice: TypeScript/JavaScript vs. Java.

I’ve lived on both sides—deep JVM experience with Groovy and Java, and plenty of time building fast-moving systems in TypeScript. After weighing the trade-offs, my position is clear:

👉 Make TypeScript your default for serverless. Keep Java for the exceptions.

Why TypeScript Should Be the Default

Faster startup and lower latency: Cold starts are the bane of Lambda functions. TypeScript (via Node.js) starts faster and keeps artifacts lean, which means fewer hiccups for end users.

Velocity and consistency: The AWS CDK feels “most native” in TypeScript. You can write infrastructure and application code in one language, sharing types and patterns. That consistency scales across teams.

Cost efficiency: Smaller memory footprints and lightweight packages mean you’re less likely to overspend on idle or spiky workloads.

Developer talent and hiring: TypeScript is accessible. Many developers come in from frontend or full-stack backgrounds. Ramp-up is fast, and shared templates mean new teams can clone, build, and ship in hours—not weeks.

Edge compatibility: CloudFront Functions and Lambda@Edge run JavaScript natively. If you want code running close to your users, TypeScript is already there.

Where Java Still Belongs

This doesn’t mean throwing out Java. It shines in very specific contexts:

• CPU-heavy workloads such as complex parsing, crypto, or data processing.

• Deep JVM ecosystems where you rely on mature Java libraries.

• Always-on, performance-critical paths where Provisioned Concurrency or SnapStart can mitigate Java’s startup costs, letting it run with excellent throughput once warm.

Think of Java as your “power lane”: not the default, but there when the job requires horsepower.

The Organizational Advantage

By choosing TypeScript as the default, you give your org:

• A single language for infrastructure and applications, which reduces context switching and speeds delivery.

• Golden templates so every team can spin up APIs, Step Functions, or event handlers with the same starter kit.

• Cross-team consistency in observability, metrics, and testing frameworks.

Meanwhile, by allowing Java as the exception, you keep the door open for high-performance or legacy-bound workloads.

Bottom Line

If you’re in a CTO seat (or advising one), the decision isn’t about picking a single “best” language forever. It’s about establishing a sensible default that accelerates most teams, while preserving flexibility where it counts.

That default is TypeScript.

That exception is Java.

Take the side that scales.