First shipped slice
Audit, slice plan, characterization tests, and the first slice shipping into production — not staging.
Legacy modernization
Modernize the system.Don't halt the business.
When the framework is two versions behind, the team that built it is gone, and every fix breaks something else — we modernize in slices, each one shipping into production. Rewrites only when they're genuinely the right answer.
Legacy modernization risks
Why legacy systems are sohard to modernize
Most consultancies push you toward a costly rewrite at the top end or band-aid patches at the bottom. Both fail the same way — they don't tell you which problem is actually the constraint. Modernization without diagnosis is just churn. We help tech leaders find the most cost-effective path off a legacy platform with minimal downtime, defects, and risk.
Balance cost and risk.
Remediate, rewrite, or something in between — the right answer is rarely the loudest one in the room.
Right-sized subsystems, not monoliths or microservices.
Seam-based modernization based on how your system actually behaves — not the architecture du jour.
YAGNI on legacy too.
Every line of code is a liability, and so are unused features still in production. Streamline functionality before you modernize it.
Value archaeology.
Find what actually drives business outcomes — so you can shrink scope, reduce cost, and eliminate risk.
Characterization tests as insurance.
We rebuild the same behaviour, not the same code. Tests prove it.
Migrate data safely.
Most failed modernizations weren't code problems — they were data problems pretending to be code problems.
Legacy system remediation
Modernize legacy systems forsoftware that lasts
Modernization is the default — not because it's safer, but because it usually wins on the math. Senior engineers have seen most legacy patterns before: the abandoned framework, the half-finished migration, the codebase that one person understood and that person left. We pattern-match across what's worked, what hasn't, and what your specific context will tolerate.
We work in slices. Each slice ships into production. Each slice provides business value on its own. You're not waiting two years for a rewrite that may never finish — you're seeing measurable improvements every few months.
The team that built it stays through stabilization. Architecture documentation goes alongside the code, not after it. We work like we'll be running the system in a year — because we usually are.
Tech & Techniques
We speak a range of languages, frameworks, and modernization techniques — and we meet your team where they are, using your tools and processes. Below is what we bring to most modernization engagements.
- automated testing suites
- release monitoring
- performance analysis & improvements
- production monitoring
- incident response
- test-driven development
- regression testing
- end-to-end testing
- integration testing
- data architecture
- software architecture
- a11y
- UI/UX
- Agile, Lean, Shape Up
- TypeScript & Node.js
- NestJS & PostgreSQL
- React Native
- AI-assisted refactoring
- your AI tools & processes
Modernize faster with AI
Speed up legacymodernization with AI tooling
Legacy codebases are fragile and poorly documented. That's exactly the work AI tooling is good at — characterization tests, codebase analysis, documentation generation, refactor scaffolding. We use it because it makes routine work faster, not because we want to mention AI on the page.
We're not dogmatic about it. Sometimes the right move is a 200-line script and a careful review. Sometimes it's an agent pipeline that runs against your whole repository. The choice is judgment, not hype.
What we don't do: bolt AI onto the same delivery and call it a transformation. AI accelerates routine work. The judgment that decides what to modernize first, and why, doesn't ship in a model.
Legacy rewrite options
When legacy rewrites make sense
Sometimes there's no avoiding it. The underlying technology is at end-of-life, or the code quality is degraded enough that maintenance costs more than starting over. We've done rewrites that enabled business-critical, system-wide innovation — and we're good at making scary work boring.
Questions to ask yourself:
- 01.
Is the underlying technology your system's built on at end-of-life?
- 02.
Are you open to reducing scope — older integrations, rarely-used features?
- 03.
Can you do rapid user discovery to enable an iterative rewrite?
- 04.
Was the codebase built modular enough to migrate piece by piece?
- 05.
Is the code quality so degraded — or the waste so deep — that remediation isn't worth it?
Outdated technologies, languages, and frameworks can make it hard to move as fast as the business needs. If you're considering a rewrite, weigh the costs, risks, and benefits carefully before investing. We can help you evaluate the decision and make the rewrite successful — and we're always going to recommend what's in your interests, not ours.
What Sets Us Apart
We've built our practice around a set of choices most consultancies won't make. Here's what those choices are — and what they mean for your engagement:
Unlike specialized service providers that only offer design or development, we help you focus on the bigger picture. This Is Software provides and coordinates the multidisciplinary skillsets you need to ship a great product.
That's why our clients keep us through stabilization, often for years — and our reviews come from the people who've lived with the code.
A track record of modernizing without breaking the business
Slice-by-slice modernization
Your system keeps running while we modernize parts of it. Your roadmap doesn't stop.
The other four are remediation. We tell you which one yours is — with numbers — before you commit.
Modernization needs more than refactoring. Here's how we deliver.
Our process guides clients through four phases, each with their own activities and deliverables. Throughout each phase, our commitment is to handle the technical complexity — and tell you the truth about trade-offs as we go.
Discover & audit
A 2-week audit of the codebase, deployment pipeline, observability, and team practices. Senior engineers walk the code, talk to your team, and find the real constraints — not the loudest ones.
You get a prioritized modernization roadmap tied to business risk, not engineering preference. We decide together what ships first, and why.
Design slices
We define the first slice — what ships, how it ships independently, and what stays untouched. Architecture and design paired from the start.
Characterization tests are written before code changes. They prove we rebuild the same behaviour, not the same code.
Build & ship
Senior engineers ship the slice. AI tooling accelerates routine work — codebase analysis, test scaffolding, refactor automation. Judgment lands where it matters.
The slice ships into production, not into staging. Real users, real load. We measure what actually changed.
Stabilise & hand off
We stay until the slice is part of your routine — not until it's "delivered." That usually means weeks of monitoring, fixes, and documentation alongside the running system.
Then we plan the next slice, or hand off cleanly. The team that built it stays through stabilization either way.
Smart questions buyers ask us
We look at the data — code quality, test coverage, deploy frequency, business risk, team capacity. Modernization is the default. Rewrite only when the cost of continuing exceeds the cost of starting over — and we prove it with numbers before recommending. In our experience, real rewrite cases are about 1 in 5 engagements.
Tell us what you have in mind. We'll figure out the right shape.
Most of our best engagements start with a 30-minute call, no slides.
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