Xero
Xero
Rebuilding enterprise payroll, without dropping the system it replaces
Rebuilding enterprise payroll, without dropping the system it replaces
A greenfield payroll platform rebuild and a legacy system that couldn't drop a step, delivered in parallel. Wave Works embedded five specialists including the tech lead from programme inception, with zero production incidents on legacy and 100% AI-assisted tooling adoption in month one.
A greenfield payroll platform rebuild and a legacy system that couldn't drop a step, delivered in parallel. Wave Works embedded five specialists including the tech lead from programme inception, with zero production incidents on legacy and 100% AI-assisted tooling adoption in month one.
5+
5+
Specialists
Specialists
4 Months. Embedded delivery squad
4 Months. Embedded delivery squad
The challenge
The challenge
The challenge
Xero, a leading global provider of cloud accounting and payroll software, embarked on Phoenix, a greenfield rebuild of its payroll platform. The hard part wasn't just the new build: the legacy system had to stay fully stable while its replacement took shape, and the programme needed architectural rigour from day one, not bodies from week six. Speed and rigour both mattered, and the team to deliver both didn't exist in-house.
Xero, a leading global provider of cloud accounting and payroll software, embarked on Phoenix, a greenfield rebuild of its payroll platform. The hard part wasn't just the new build: the legacy system had to stay fully stable while its replacement took shape, and the programme needed architectural rigour from day one, not bodies from week six. Speed and rigour both mattered, and the team to deliver both didn't exist in-house.
Xero, a leading global provider of cloud accounting and payroll software, embarked on Phoenix, a greenfield rebuild of its payroll platform. The hard part wasn't just the new build: the legacy system had to stay fully stable while its replacement took shape, and the programme needed architectural rigour from day one, not bodies from week six. Speed and rigour both mattered, and the team to deliver both didn't exist in-house.
What we built
What we built
What we built
Wave Works embedded five specialists into Xero's sprint cadences, including the technical lead from programme inception, owning architecture and domain modelling before a line of production code was written:
Foundational Phoenix architecture
Domain modelling and platform direction, led from day one
Shared platform components
Kafka messaging infrastructure and service boilerplate used across the programme
Three Phoenix work streams in parallel
Calculations, Outputs and Inputs, delivered at sprint pace
Frontend delivery
TypeScript and React integrated into the Phoenix platform
Legacy stability throughout
KTLO rotation keeping the existing system running while its successor was built
Foundational Phoenix architecture
Domain modelling and platform direction, led from day one
Shared platform components
Kafka messaging infrastructure and service boilerplate used across the programme
Three Phoenix work streams in parallel
Calculations, Outputs and Inputs, delivered at sprint pace
Frontend delivery
TypeScript and React integrated into the Phoenix platform
Legacy stability throughout
KTLO rotation keeping the existing system running while its successor was built
Foundational Phoenix architecture
Domain modelling and platform direction, led from day one
Shared platform components
Kafka messaging infrastructure and service boilerplate used across the programme
Three Phoenix work streams in parallel
Calculations, Outputs and Inputs, delivered at sprint pace
Frontend delivery
TypeScript and React integrated into the Phoenix platform
Legacy stability throughout
KTLO rotation keeping the existing system running while its successor was built
The squad adopted AI-assisted development tooling across the team in the first month, embedded into standard engineering practice rather than run as a one-off pilot, accelerating delivery velocity across both workstreams.
The squad adopted AI-assisted development tooling across the team in the first month, embedded into standard engineering practice rather than run as a one-off pilot, accelerating delivery velocity across both workstreams.
The outcomes
The outcomes
The outcomes
Greenfield and legacy delivered in parallel
One squad, two concurrent workstreams, no split focus.
Zero production incidents
On the legacy system throughout the transition
Foundational architecture delivered
Domain model and shared components now carrying the programme
100% AI-assisted tooling adoption
Within the first month, embedded as standard practice
Tech-lead continuity from day one
Architectural decisions owned from inception, not inherited mid-flight
Greenfield and legacy delivered in parallel
One squad, two concurrent workstreams, no split focus.
Zero production incidents
On the legacy system throughout the transition
Foundational architecture delivered
Domain model and shared components now carrying the programme
100% AI-assisted tooling adoption
Within the first month, embedded as standard practice
Tech-lead continuity from day one
Architectural decisions owned from inception, not inherited mid-flight
Greenfield and legacy delivered in parallel
One squad, two concurrent workstreams, no split focus.
Zero production incidents
On the legacy system throughout the transition
Foundational architecture delivered
Domain model and shared components now carrying the programme
100% AI-assisted tooling adoption
Within the first month, embedded as standard practice
Tech-lead continuity from day one
Architectural decisions owned from inception, not inherited mid-flight
Built to hand over.
Built to hand over.
Built to hand over.
Phoenix's architecture was documented as it was designed, and the KTLO rotation progressively transferred BAU ownership back to Xero's teams, with skills retained in-house across both workstreams and no over-reliance on external delivery as the programme ramped.
Phoenix's architecture was documented as it was designed, and the KTLO rotation progressively transferred BAU ownership back to Xero's teams, with skills retained in-house across both workstreams and no over-reliance on external delivery as the programme ramped.
“
Consultants embedded into a complex, fast-moving enterprise programme, delivering across both greenfield and legacy workstreams with consistency and professionalism throughout.
Dean Hand
Line Manager
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