Between legacy and modern systems
Hands-on experience across generations of systems—and especially in designing the path between them.
Software Engineering Studio · Barcelona
We build what comes next.We modernize the software your business already relies on.
We help companies define, build and modernize products, platforms and systems when technical decisions have a real impact on the business—from analysis and architecture through production and continued evolution.
ENGINEERING / TRANSITIONACTIVE PATH / BUILD
INPUTA real business need
OUTPUT01 BUILDSoftware ready for production and continued evolution.
Evolve
WHEN SOFTWARE MATTERS
The challenge is rarely just writing code.
The challenge begins when the code embodies processes, decisions, data and dependencies the business cannot afford to lose.
01The system works, but every change costs more.Existing software that is starting to hold the business back.
The application contains years of processes, data and business rules. Before replacing technology, we need to understand which knowledge must be preserved and which historical decisions no longer make sense.
SYSTEMLegacy application
Modernize an existing system RulesDataIntegrations
02You have something important to build.The opportunity is real; it still needs a sound technical leadership.
We define the product, architecture, data and integrations before turning the initiative into working software. We can then stay involved through technical leadership and delivery.
INPUTBusiness opportunity
Build a product or platform ProductArchitecture
03You have requirements, but the solution is not sufficiently defined.Reduce uncertainty before committing to an investment.
A feature list alone does not define scope, architecture, dependencies or risk. An assessment turns those unknowns into evidence that can support a decision.
DEFINERequirements Decision
Explore technical assessments ScopeRiskOptions
TWO POINTS OF ENTRY
Build what comes next. Evolve what already matters.
PRODUCT & PLATFORM ENGINEERING
From a business need to software built to evolve.
We define, design and build products, platforms and systems from the earliest decisions through production and continued evolution.
Product & Platform Engineering- 01INPUTBusiness needOpportunity · Goal · Constraints
- 02DESIGNDefine & architectScope · Data · Interfaces
- 03OUTPUTProduct / platformProduction · Feedback · Evolution
TECHNICAL OWNERSHIP
LEGACY & BUSINESS SYSTEMS MODERNIZATION
Evolve without losing years of accumulated knowledge.
We first identify what must be preserved, then design a controlled transition to an architecture that can keep evolving.
Legacy & Business Systems Modernization- 01CURRENTLegacy systemRules · Data · Integrations
- 02TRANSITIONAssess & decideRetain · Refactor · Replace
- 03TARGETModern platformAPIs · Delivery · Evolution
BUSINESS KNOWLEDGE
REAL WORK
Engineering you can inspect.
We prefer to explain the problem, the constraints and the decisions made—not display a technology list.
01Condis SupermercatsBusiness Systems Modernization · Operational application
Modernize business software while preserving knowledge and operations.
A system with years of rules, data and dependencies cannot be modernized by copying screens. The first step is to recover enough knowledge to decide what to preserve, what to change and how to migrate with traceability.
View the Condis case study- 01DISCOVERRecover knowledgeApplication · data · users
- 02DECIDEDecide what changesPreserve · redesign · migrate
- 03TRANSITIONBuild the transitionArchitecture · data · delivery
- 04VERIFYVerifyTraceability · behavior · UAT
02eVinsProduct Engineering · Frontend and product collaboration
Evolve an existing SaaS around real product, customer and operational constraints.
Rabassoft worked on defined frontend and product areas while the eVins team retained responsibility for the platform and backend. The work combined technical modernization with pragmatic decisions shaped by existing customers and data.
View the eVins case study- 01CURRENTExisting SaaSCustomers · modules · constraints
- 02HEALTHTechnical foundationAngular · typing · architecture
- 03EVOLVEFrontend evolutionStandalone · lazy routes · Signals
- 04DECIDEPragmatic decisionBest viable path
03Schema EngineRabassoft Engineering / Open Source · Experimental
Validated metadata, explicit application decisions.
An engine for reducing repeated interface implementation: it compiles metadata into normalized definitions while keeping data, operations and authorization under application control.
Explore Schema Engine- 01INPUTSchema + UI SchemaCurrent data and presentation metadata
- 02COMPILENormalized definitionValidation · compatibility · diagnostics
- 03RUNTIMEControlled executionSnapshots · interaction · validation · operations
- 04BOUNDARYApplication decisionAccept · reject · defer
BEFORE BUILDING
A detailed estimate should not be built on assumptions.
When material uncertainty remains, we reduce it before committing to a larger investment. An assessment does not manufacture certainty: it turns open questions into useful decision-making evidence.
Explore technical assessmentsPROJECT DEFINITIONUNCERTAINTY DECISION
- 01NEEDBusiness needGoals · impact · constraints
- 02DISCOVERScope the problemStakeholders · data · dependencies
- 03DEFINEDesign the directionScope · architecture · risks
- 04ROADMAPImplementation planPhases · investment · next step
LESS UNCERTAINTY
LEGACY MODERNIZATIONKNOWLEDGE TRANSITION
- 01SYSTEMExisting systemApplication · data · integrations
- 02RECOVERRecover knowledgeRules · dependencies · risks
- 03DECIDEChoose transitionRetain · refactor · replace
- 04TRANSITIONModernization roadmapMigration · phases · continuity
CONTROLLED TRANSITION
HOW WE WORK
A process that keeps context, decisions and delivery connected.
Each phase reduces a different uncertainty and leaves a clear outcome for the next, without losing accumulated project context.
PROJECT CONTEXT
01Understand before you commit.Objectives, processes, data, constraints and dependencies.+
We work with the people who know the business and the system to turn scattered information into a sufficiently complete view of the problem.
OUTPUTProblem sufficiently defined
02Decide before implementation.Alternatives, priorities, trade-offs and risks.+
We compare options and make explicit the reasons for the chosen direction, including the discarded alternatives and their consequences.
OUTPUTDefensible decision
03Design a base that can evolve.Architecture, data, interfaces, boundaries and integrations.+
We turn earlier decisions into a coherent architecture, creating a sound foundation for both the first delivery and what follows.
OUTPUTTarget architecture
04Convert decisions to software.Implementation, integration, testing and delivery.+
Technical leadership remains connected to delivery so decisions do not lose context when they reach the code.
OUTPUTImplemented increment
05Verify before accepting.Behavior, integration, security, performance and quality.+
Compiling or appearing correct is not enough. Acceptance relies on evidence suited to the change and its risk.
OUTPUTEvidence before completion
06Evolve after production.Feedback, new needs, roadmap and technical continuity.+
Production is not the end. Real-world feedback and changing business needs drive another iteration while preserving accumulated knowledge.
OUTPUTSoftware that continues to evolve
WHY RABASSOFT
A small structure works when it strengthens accountability.
Decisions connected to delivery
Those involved in technical decisions remain involved during implementation.
Decisions before promises
We do not accept scope, budget or timeline commitments that we cannot defend technically.
Continuity without lock-in
We document key knowledge so the system can continue evolving with or without Rabassoft.
AI-ASSISTED ENGINEERING
AI-assisted engineering. Human accountability.
We use AI when it helps us understand a system more deeply, analyze more information, automate repetitive work or shorten specific engineering cycles.
It does not replace architecture, testing, review or accountability for the outcome.
How we use AICONTROLLED WORKFLOWHUMAN ACCOUNTABILITY
- 01CONTEXTProject memoryArchitecture · decisions · constraints
- 02SCOPEBounded accessFiles · permissions · allowed actions
- 03AGENTAnalyse / implementExecution inside the authorised scope
- 04VERIFYEvidenceTests · check · build · review
- 05HUMANDecide / approveAccountability remains human
RESPONSIBILITY
VERIFY FAILEDRETURN TO IMPLEMENTATIONVERIFY AGAIN
BLOG
Engineering you can inspect.
Analysis and lessons from building, modernizing and evolving software.
Read the latest articles in the Blog · ES.
START / CONVERSATION
Do you have something important to build—or a system that needs to evolve?
You do not need to arrive with a predetermined solution, a locked specification or a number that someone is expected to validate.
The first conversation is about fit. When material uncertainty remains, work will usually begin with a technical assessment before a larger investment is committed.