Modernize legacy financial systems without a multi-year transformation contract. Get senior nearshore engineers from LATAM who can work incrementally alongside your existing core, building the API layers, integrations, and services that move you forward, while the systems that process your transactions keep running.
Trusted by FinTech innovators across the U.S. and LATAM
Trio provides fintech engineering services for teams that need to move quickly without compromising uptime, security, reliability, or compliance. Our engineers bring hands-on experience building financial software in production environments without disrupting existing services.
We provide engineers who can execute the roadmap you already have and integrate into existing teams without a program-management layer priced into every hour.
Start Hiring NowA legacy core is full of code that looks wrong and is load-bearing. Our engineers have worked in regulated systems where the strange-looking function exists because a regulator required it. They can often recognize the code, and if they don’t, then they ask before they simplify.
Start Hiring NowEngineers implement strangler-fig migration, API layers over existing cores, and ensure the coexistence between old and new software so their work can continue to deliver value as it is modernized going forward.
Start Hiring NowModernization outlasts most vendor relationships. 95% developer retention means the engineer who learned your batch schedule can be accessed later.
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Why Trio
We help teams ship enterprise apps that behave predictably in production. Our fintech developers stay because they grow, and that experience shows up in cleaner releases, better handoffs, and fewer late-stage surprises.
| Criteria | Trio | Internal Hiring | Marketplace |
|---|---|---|---|
| Time to find a developer | 0–3 weeks | 4–16 weeks | 4–16 weeks |
| Recruiting Fee | None | 15%–40% | None |
| Quality Guarantee | Yes | No | No |
| Failure Rate | Very Low | Low | High |
| Pre-Screened Candidates | Yes | No | No |
| Deep Technical Validation | Yes | No | No |
| Termination Costs | None | Very high | High |
| Start Now |
Case Studies
FinTech founders and CTOs work with Trio’s engineers for one reason: confidence.
Trio matched Cosomos with skilled engineers who seamlessly integrated into the project.
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Our access to the global talent pool ensured that Poloniex’s development needs were met.
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We provided UBERDOC with engineers who already had the expertise needed.
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Trio introduced an integrated ecosystem for centralized and automated data gathering.
Learn MoreDiscuss your core platform, integration estate, modernization sequence, and constraints.
Review engineers matched to your stack, your core provider, and the pace you need to work at.
You interview the engineers and choose who fits your team best.
Engineers join your program without a mobilization phase.
Ongoing alignment, performance tracking, and support from Trio.
Talk to a specialist
Work with fintech engineers who understand regulated environments, complex integrations, and the cost of downtime. Scale securely while keeping full ownership and control. You own all code and IP, and if an engagement ends, transitions get documented so institutional knowledge stays on your side.
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Trio engineers are highly skilled at their jobs, and fully vetted by the Trio team BEFORE their resumes got to my desk. Being able to see a video of a Trio engineer walking me, in English, through the sample project he developed for Trio was a real game-changer.
When I started my new job last year, I specifically requested Trio and we have built up two teams of Trio developers. They are intelligent, ethical, hard-working, efficient, produce quality work and so kind and fun to work with. I can’t say enough good things about them… You can’t go wrong with Trio!
Trio was incredibly effective in determining our project’s needs and solving them with the right team. The engineering team had the exact expertise we needed, and provided proactive communication during development. The overall experience was clear and reliable.
Curated by
10 Years of Experience
Fintech leaders work with Alex to build engineering teams that scale securely and move fast. With over a decade in software outsourcing, he helps companies hire high-performing developers suited for regulated environments and complex financial systems. After co-founding Trio with his partner Daniel, Alex now focuses on helping fintech teams hire top software talent from Latin America and shares practical insights drawn from real hiring and delivery experience.
September 18, 2026
Arguably, forming a strategy for something like banking core modernization is the easiest part of the process. Executing that plan, without negatively affecting your customers or creating unnecessary downtime, is the difficult part.
Let’s look at what actually needs to get built once the strategy is already decided, and who can safely build it next to a core system that’s been processing real transactions since before most of the engineering team was born.
To get skilled fintech developers on your team who can help you execute your enterprise modernization successfully, request talent.
For a bank, credit union, or insurer running a legacy core, the consensus on approach has never been stronger: incremental modernization, API layers, progressive migration off the monolith.
What’s actually missing is people who can execute it without burning out the one or two engineers who already understand how the existing system actually behaves.
The numbers back this up. Roughly 90% of US banking core software is considered legacy, according to industry analysis from TechMagic.
AWS’s own published guidance on core banking modernization reports that 71% of mainframe teams describe themselves as understaffed, with the pool of COBOL-proficient engineers continuing to shrink as practitioners retire faster than new ones enter the field.
A transformation contract gives an institution a roadmap and a program manager, but the actual constraint is that a shrinking handful of people understand the core well enough to touch it safely.
Large legacy modernization rewrites fail often. This can be attributed to the fact that rewriting decades of undocumented, accumulated business logic all at once carries incredible risk.
Several major European banks have abandoned full replacement projects after years of development and hundreds of millions in sunk cost, a pattern that’s become common enough to be its own cautionary genre in the industry press.
The alternative is building new functionality as services around the existing core and routing traffic to them progressively rather than attempting a cutover.
Just keep in mind that attempting to re-architect the core before the underlying data architecture is stabilized reliably produces longer timelines and more risk, so make sure that you carry the process out in the right order.
Wrapping a legacy core in an API layer is fast, comparatively cheap, and makes an institution look modern from the outside almost immediately.
It’s often the right first move, since it unblocks mobile and digital channels without waiting on the core itself to change.
But underneath the wrapper, the core is still batch-oriented and still expensive to maintain, and the technical debt underneath keeps accruing regardless of how modern the layer on top looks.
This means it’s just the first step in an extended sequence, and if you treat it as the end state you will probably end up dealing with the same constraint again in a few years, with less runway and fewer COBOL-proficient engineers left to call on than they had the first time around.
The actual coding requires having actually worked inside one of these systems rather than around them.
A strong generalist engineer looks at a legacy core and sees a refactoring opportunity, which might be the right decision in a normal app. However, you need someone who knows to ask why something is the way it is before changing it, and who already knows that in a regulated institution.
The ultimate goal of modernization is to meet user expectations and keep up with whatever competitors are doing.
Think of things like real-time balances instead of overnight settlement, feature cycles measured in weeks rather than waiting for a quarterly release window, real-time payment capability, and self-service capability that measurably reduces call center volume.
Staff augmentation puts engineers on your program under your own direction. It’s usually the right fit when engineering leadership and a defined sequence already exist internally.
A dedicated team is the way to go if your workstream needs real continuity across years, like for a genuinely multi-year modernization effort.
Project outsourcing suits a defined build with a defined scope.
Whatever model you end up choosing, remember that continuity matters more than the specific contract structure, since the expensive knowledge here is what engineers learn about your specific systems over time.
Trio’s LATAM engineers run $40-90 an hour, typically 30-50% below US equivalents for comparable seniority.
On the other hand, consultancy blended rates bundle in program management, delivery oversight, and account infrastructure on top of the engineering itself.
If you don’t have any of those functions internally, that bundling is a genuine product worth paying for. If those functions already exist in-house, that same institution is paying twice for management it doesn’t need.
COBOL and mainframe specialists command a real scarcity premium, commonly cited somewhere in the $125,000 to $150,000-plus range depending on seniority and region, and that premium keeps climbing as the pool shrinks.
But most modernization work doesn’t actually require COBOL engineers at all. It requires engineers who can build the APIs, services, and integrations that interact with a core they don’t need to rewrite.
We recommend that you ask for engagements of genuinely comparable complexity. Find out what actually happened the last time something broke in production on their watch, and ask specifically how they’ve handled a change that touched a batch window before.
One question does more work than the rest combined: ask a prospective partner what they’d actually do if they found a function in your core that looks redundant and has no documentation attached to it.
The answer tells you directly whether they’ve worked inside a regulated institution before.
To be connected with developers that have guaranteed experience, book a discovery call.
Frequently Asked Questions
Engineers can typically join within days of selection rather than after a mobilization phase, since candidates are pre-vetted before the engagement even begins.
Look for evidence of comparable complexity rather than comparable stack, references you can actually follow up with, and a clear, specific answer about how they handle undocumented legacy behavior when considering an enterprise development partner.
Engineering capacity can scale up or down across the phases of a modernization program without restarting the engagement or losing accumulated system knowledge.
Compliance in enterprise development engagements is handled through access controls, audit trails, environment separation, and evidence practices aligned to whichever frameworks the institution actually operates under.
With Trio, the client owns all source code and intellectual property by default, from day one.
The main risks in legacy modernization include documented behavior, intertwined logic in single code paths, batch window dependencies, and point-to-point integrations whose blast radius isn’t visible from the code alone.
You can keep engineers from breaking legacy systems by staffing with developers who actually have regulated-environment experience, who confirm why unusual code exists before changing it, and by pinning existing behavior with tests before modifying it.
A consultancy provides strategy, program management, and delivery ownership. Staff augmentation provides engineering capacity under your direction, which suits institutions that already have a modernization plan and engineering leadership in place.
Incremental approaches to modernization are designed to happen without disrupting live systems, running legacy and modern systems in parallel and migrating workloads gradually with verification at each stage.
Modernization programs typically run for years rather than months, which is why continuity of engineering staff matters more than the contract structure chosen at the start.
An API layer over a legacy core is fast and unblocks digital channels, but it doesn’t change the underlying batch-oriented system. It’s a sequencing decision rather than a destination.
Usually, COBOL developers are required less than expected. Most modernization work is modern-stack engineering around the legacy system, APIs, services, and integrations, rather than rewriting the core itself.
The strangler fig pattern replaces a legacy system gradually by building new functionality as services around the existing core and progressively routing traffic to them, avoiding a high-risk cutover.
Core banking modernization is the transition from legacy, batch-oriented mainframe systems toward API-driven architecture that supports real-time processing, usually delivered incrementally rather than as a single replacement.
For financial institutions, enterprise software development usually means modernizing or integrating with legacy core systems, building API layers, and delivering digital channels without disrupting transaction processing.
An enterprise software development company builds and maintains large-scale systems for established organizations, typically involving integration with existing platforms rather than greenfield development.
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