Legacy Application Modernization Company
Legacy Application Modernization.
Legacy Application Modernization.
Without the Downtime.
Your legacy system is charging you by the hour. Every developer hour spent on workarounds, every deployment weekend, every feature blocked by technical debt is a cost that compounds. We replace legacy applications incrementally using the strangler fig pattern. Your users never notice.
Submit brief → call within 48 hours → scoped proposal in 3 days → audit starts within 1 week
Zero downtime migrations75+ systems modernized100% code ownership on delivery90-day post-launch support
Since this page loaded
$0.00
in legacy overhead costs*
The Legacy Application Problem
The overhead your team carries every sprint. And what your roadmap looks like after modernization.
Every item on the left column has a dollar amount attached to it. The right column is what your team gets back.
Your legacy overhead today
Deployment weekends consuming senior engineers
Releases require manual coordination. Rollback is a
four-hour emergency. Deployment cadence is monthly at
best.
Feature development blocked by architecture constraints
Every new feature requires understanding a tightly-coupled
codebase built ten years ago by developers who have left.
Scale failures under load that users report before
monitoring does
The system was never designed for current traffic. You
discover the ceiling when it breaks, not before.
Security patches applied manually, tested in production
No automated security scanning in the pipeline. CVEs are
discovered in incident reports, not build logs.
Recruiting blocked by technology choices from 2009
Top engineers see the stack and decline interviews. The
talent market has moved. Your codebase has not.
After legacy application modernization
Automated CI/CD with zero-downtime deploys
Deployments run on a push. Rollback is a one-click revert.
Teams ship features multiple times per week.
Independent services that teams deploy without
coordination
Each service has clear boundaries. Teams move at their own
pace. No more waiting on the release train.
Auto-scaling infrastructure that grows with traffic
Load tests run before every launch. Infrastructure scales
horizontally. You monitor headroom, not incidents.
Automated security scanning in every build pipeline
Dependency vulnerabilities surface in the build log, not
in a security audit. CVEs are closed in hours, not months.
Standard modern stack that the engineering market wants to
join
Interviews convert. Engineers see the architecture and ask
about scope for growth. Hiring velocity improves.
Pain · IT team at legacy server maintenance
Legacy Overhead Cost Calculator
Your legacy system is billing your team by the hour. See the running tab.
Adjust your team size, the percentage of developer time consumed by legacy overhead, and your average hourly rate. The counter runs in real time as you read this page.
Accumulated legacy overhead since you opened this page
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and counting, this counter resets if you refresh
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per hour
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per day
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per year
Adjust your numbers
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Developers on your team20 developers
Time spent on legacy workarounds30%
overhead
Average developer hourly rate$100/hour
*Calculation: (developers × overhead% × hourly rate × 40 hours × 52 weeks). Excludes infrastructure, security, recruiting costs. Real cost is higher.
Get A Modernization Proposal
What your legacy overhead costs include
Developer hours on workarounds and maintenance
The largest visible cost. Senior engineers debugging
systems instead of building features.
Deployment coordination overhead
Blocked release windows, manual rollback procedures,
cross-team coordination for every deploy.
Incident response and recovery time
Outages consume engineering time at 3x normal rate.
Legacy systems fail under load. There is no
auto-recovery.
Recruiting premium for legacy technology specialists
Hiring engineers who know the legacy stack costs more.
Onboarding takes longer. Most modern engineers decline.
The modernization return on investment case
Most legacy application modernization projects recoup their cost within 18 months of completion. The ongoing overhead eliminated exceeds the one-time engagement cost by year two. The calculation uses the same numbers above.
Get your scoped proposal and cost comparison →How Legacy Application Modernization Works
Five phases. No dark launch weekends. No user disruption between phase one and phase five.
Scroll horizontally to see the full methodology. Every phase delivers independently. If a phase needs to pause, the previous phase keeps serving production traffic.
01
Phase one
Technical audit and dependency mapping
Full codebase audit, external dependency inventory, integration surface mapping, security vulnerability scan, and data flow documentation. Every risk is ranked before any build work begins.
Delivered: Architecture blueprint, risk register, migration
decision record
02
Phase two
Strangler fig strategy and parallel environment setup
Migration roadmap finalized. Adapter layer designed. New architecture repository created and CI/CD pipeline established. The modern environment begins receiving shadow traffic before any real migration starts.
Delivered: CI/CD pipeline, parallel environment, first
service boundary
03
Phase three
Incremental component replacement
Legacy components are replaced one service boundary at a time. Each new service is deployed and receiving real traffic before the next component migration begins. The legacy system continues to serve anything not yet migrated.
Delivered: Live modern services alongside legacy, per-sprint
handoff notes
04
Phase four
Data migration and validation
Parallel writes to both legacy and modern databases. Data consistency validation runs continuously. Load tests against production data volumes. No cutover happens until the new database has been proven under real production conditions.
Delivered: Data parity report, load test results, cutover
readiness certificate
05
Phase five
Legacy decommission and handoff
Legacy system traffic routed to zero after final validation in production. Full documentation: architecture diagrams, runbooks, on-call playbooks, and data model guides. 90-day hypercare support period. Code and IP transfer to your team.
Delivered: Complete documentation, 90-day support, full IP
transfer
Targeted modernization
$120K to $250K
12 to 18 weeks. Single system or domain modernized.
Full platform migration
$250K to $500K
20 to 28 weeks. Full application stack replaced.
Migration Architecture
The strangler fig pattern: how traffic migrates from legacy to modern without disrupting users
Click any layer to see what lives inside it, what it is responsible for, and what happens if it fails. The strangler fig allows any layer to be replaced without taking the others offline.
Legacy Monolith
Continues serving routes not yet migrated
Legacy traffic: 100%
Router / Adapter Layer
Routes each request to legacy or modern based on migration
state
The strangler
Modern Platform
Receives migrated routes. Grows toward 100% of traffic
Growing: 0% to 100%
Legacy Monolith
The legacy system continues operating at 100% of production traffic on day one of the engagement. It is never shut down, never put in maintenance mode. Components are extracted one at a time, and the legacy system serves everything that has not yet been migrated. When the migration is complete, traffic drops to zero and the legacy system is decommissioned.
Never shut down mid-migrationTraffic: 100% to 0%Always rollback-safe
Migration state at each phase
Phase 1 to 2Legacy: 100%
Phase 3 (mid)Legacy: 60%
Phase 5 completeLegacy: 0%
Router / Adapter Layer
The adapter layer is the "strangler fig" itself. It intercepts every request and routes it to either the legacy system or the modern platform depending on whether that route has been migrated yet. It also handles protocol translation between old and new systems during parallel writes, and provides the rollback mechanism at any point in the migration.
Route-level migration controlProtocol translationInstant rollback
Router responsibilities
Traffic routing rules
Per-route configuration that can be toggled without a
deployment.
Parallel write coordinator
Writes to both databases during data migration phase.
Flags discrepancies.
Modern Platform
The modern platform begins receiving real production traffic as soon as the first service is migrated. It is not tested in staging and launched into production cold. It runs in production from phase three, accumulating performance data and proving itself under real load before the legacy system's traffic share reaches zero.
Live in production from phase 3Cloud-native architectureAuto-scaling infrastructure
Platform capabilities delivered
Kubernetes on AWS EKS or GCP GKE
Container orchestration. Auto-scaling. Self-healing.
Rolling deployments.
CI/CD pipeline with staging gates
Every commit tested. Every merge to main deploys to
staging. Production requires manual gate.
Client Result: AWS Cloud-Native Application Modernization
Legacy monolith to cloud-native microservices. Zero user disruption across the full migration.
Zero
user disruptions during the full migration from legacy monolith
to modern platform
Continuous
deployment cadence post-migration, replacing monthly high-risk
release cycles
Microservices
architecture replacing tightly-coupled monolith, with
independent team deployments
Proof · post-modernization launch milestone
The organization
A SaaS and B2B platform with an established user base operating a legacy monolithic application that had accumulated years of tightly-coupled architecture. The system powered core product features and processed real-time user data. Any migration approach that risked user disruption was not viable.
SaaS and B2B platformCloud-Native Modernization
The problem
The legacy monolith caused slow release cycles, frequent production outages under load, and tightly-coupled architecture that made independent team deploys impossible. Deployment processes were risky and manual. The system could not scale to meet user growth without significant production incidents.
Delivered
- Cloud-native microservices on Kubernetes (AWS EKS)
- CI/CD pipeline replacing manual deployment processes
- Zero production user disruptions during full migration
- Containerized services with auto-scaling and self-healing
What Makes This Different
Three things that separate a zero-downtime migration from a very expensive weekend outage.
01
No big-bang rewrites. The strangler fig replaces components
while the system stays live.
A big-bang rewrite means shutting down a production system, building a replacement in isolation, and hoping it works when you turn it back on. Most fail, cause outages, or deliver a system that cannot handle real production load. The strangler fig pattern replaces components one service boundary at a time while the legacy system continues to serve production traffic. There is no moment where everything is offline. There is no single cutover that can fail. There is always a rollback.
02
Zero-downtime cutover. The modern platform proves itself in
production before the legacy system retires.
The modern platform receives real production traffic from the moment the first service is migrated. Not staged traffic. Not synthetic load tests. Real users. This means by the time the legacy system's traffic share reaches zero, the modern platform has already been running in production for weeks or months. It has proven itself at production scale, under real data, with real failure modes surfaced and resolved. The cutover is not a risk event. It is the formalization of something that is already working.
Enterprise software services03
Full code ownership. On delivery day, every line of the modern
platform belongs to your team.
No licensing. No proprietary tooling your team cannot read or extend. No ongoing dependency on us to make changes. The code ships with architecture documentation, runbooks, on-call playbooks, and a data model guide that any engineer you hire can use to understand the system without calling us. The 90-day hypercare period is a support window, not a vendor lock-in mechanism. After it ends, your team runs the platform independently. That is the outcome we are optimizing for.
Custom software developmentFrequently Asked Questions
What CTOs and engineering leads ask before engaging.
How long does legacy application modernization take?
Legacy application modernization typically runs 16 to 28 weeks depending on system complexity, integration surface, and migration approach. Every engagement starts with a two to three week technical audit that maps the full system before any build work begins. The audit produces a risk-ranked migration plan with a phase-by-phase timeline. For more complex systems or larger codebases, phased programs may run 12 to 18 months across multiple increments.
Do we need to shut down the legacy system during modernization?
No. The strangler fig pattern allows the modern platform to replace legacy components incrementally while the legacy system continues to serve production traffic. Your users never experience downtime. The legacy system is decommissioned only after the modern platform has proven itself in production, not before. See our cloud-native development services for the architecture that makes this possible.
What happens to existing data during the migration?
Data migration is planned in the architecture phase before any code is written. We design the data pipeline alongside the new system schema, run parallel writes to both systems during the transition period, validate data consistency at every phase, and only cut over once the new database has been proven against production data volumes. Data migration is never a big-bang event. It is a continuous, validated process.
How do you handle existing integrations and third-party systems?
Every integration is mapped in the technical audit and connected through an adapter layer in the new architecture. The adapter layer allows the modern system to communicate with legacy integrations during the transition period. Each integration is migrated independently so a delay in one never blocks the broader project. Third-party integrations that are deprecated are documented and their replacement planned before migration begins.
How much does legacy application modernization cost?
Legacy application modernization typically runs between $120,000 and $500,000 depending on system complexity, codebase age, integration surface, and migration strategy. We scope before we quote. Every proposal includes a line-by-line breakdown with phase-by-phase pricing and clear scope boundaries. The technical audit deliverable (weeks 1 to 3) is priced separately and produces the migration plan that informs the full engagement price. See our pricing guide.
Is This the Right Engagement for You?
We are direct about fit before any commitment.
Good Fit
You have a production system that is blocking team velocity
and you cannot afford a big-bang rewrite or a downtime event
to replace it
Your engineering team can participate in weekly sprint
reviews and your CTO or VP of Engineering can make
architecture decisions during the engagement
You want full code ownership and the ability to extend the
modern platform with your own team after the engagement
ends
You have a clear business case for modernization: reduced
maintenance overhead, unblocked feature development, improved
reliability, or recruiting competitiveness
Your system has been in production for 5 or more years with
limited refactoring and your team has accumulated significant
maintenance overhead
Not A Fit
Your system is under 3 years old and the primary concern is
code quality rather than architectural legacy. A refactoring
engagement may be more appropriate.
You need the modernization completed in less than 8 weeks.
The technical audit alone takes 3 weeks. Compressed timelines
bypass risk assessment and create the very outages you are
trying to avoid.
Your total budget is under $80,000. Below this threshold, the
audit and migration infrastructure cannot be properly
resourced.
Your organization does not have an internal technical
stakeholder who can review architecture decisions and approve
migration phases.
Not sure? Tell us about your system and we will tell you honestly whether modernization makes sense right now.
Book A Technical Strategy Call
Tell us about your legacy system.
We review every brief and respond within two business days. No commitment. No pitch.
Form
Submit brief → call within 48 hours → audit scoped in 3 days → audit starts within 1 week
48 hours
Response time
3 days
Proposal scoped
75+
Systems modernized
100%
Code ownership
Brief received.
We will review your system and send a scoped proposal within 3 business days.
Pre-footer · lead architect at new modern architecture
Ready to replace your legacy system without the downtime?
No commitment. No pitch.