SaaS Development Company
FISTA Solutions builds and scales B2B SaaS products: multi-tenant architecture, subscription billing, role and permission models, enterprise readiness for security reviews, AI features that justify their cost, and the platform engineering that keeps unit economics healthy as you grow.
- 150+
- projects delivered
- 50+
- companies served
- 99.9%
- verified uptime
- 47%
- efficiency gains
- 12+
- countries reached
What we build
What does a SaaS development company build?
FISTA builds SaaS MVPs, multi-tenant platform foundations, subscription billing and entitlements, enterprise readiness features such as SSO and audit logs, AI capabilities inside the product, and the scale work that keeps latency and cloud cost under control.
- 01
SaaS MVPs
The smallest product that proves the bet, built on foundations that will not need replacing at the first ten customers.
0 to 1 - 02
Multi-tenant architecture
Tenant isolation, data partitioning, noisy-neighbor controls, and per-tenant configuration without forking the codebase.
Platform - 03
Billing and entitlements
Plans, usage metering, trials, proration, and entitlement checks that match what sales actually sells.
Monetization - 04
Enterprise readiness
SSO and SCIM, granular roles, audit logs, data export, and the documentation that gets you through procurement security review.
Enterprise - 05
In-product AI features
Copilots, summarization, and agents built with evaluation harnesses and cost controls, so the feature does not erode gross margin.
AI - 06
Scale and reliability
Performance profiling, query and cache strategy, background job architecture, and cloud cost engineering as usage grows.
Scale
Requirements
Which requirements shape SaaS development?
SaaS products are judged by buyers who run security reviews, by users who abandon slow software, and by boards who watch gross margin. That means tenant isolation must be provable, enterprise features must exist before enterprise deals, and AI features must be cost-modeled per user.
| Requirement | What it means here | How FISTA builds to it |
|---|---|---|
| Tenant isolation | One customer must never see another's data, and you must be able to prove it. | Isolation enforced at the data-access layer, tenant-scoped tests in CI, and documented isolation model for security questionnaires. |
| Enterprise procurement | Deals stall on SSO, audit logs, data residency, and questionnaires. | SSO and SCIM, exportable audit logs, region options, and a maintained security documentation pack. |
| Usage economics | AI and infrastructure cost scales with usage, not revenue. | Per-tenant cost attribution, model routing and caching for AI features, and margin dashboards alongside product metrics. |
| Performance | Slow software loses renewals quietly. | Performance budgets per critical path, query and N+1 discipline, and profiling built into the release process. |
| Data portability | Customers demand export and deletion. | Documented export formats, deletion workflows honoring retention obligations, and evidence of completion. |
Where AI fits
Where do AI agents fit in saas?
AI fits SaaS products where it compresses a user's work inside your existing surface: summarizing records, drafting content, answering questions from tenant data, and running multi-step workflows. Each feature needs an evaluation harness, a cost model per active user, and a fallback when the model fails.
- 01
In-product copilot
Answers questions and performs actions inside your product scoped to the tenant's data and the user's permissions.
- 02
Summarization features
Compresses long records, threads, and documents into the summary users would otherwise write by hand.
- 03
Workflow agents
Executes multi-step tasks inside your product with approval gates and traces the customer's admin can inspect.
- 04
Support deflection agent
Answers product questions from your documentation with citations, escalating gaps to your support team as content requests.
- 05
Onboarding and migration agent
Maps and imports a new customer's data from spreadsheets and competitor exports, flagging ambiguity for human confirmation.
Cost and timeline
How much does SaaS development cost, and how long does it take?
Cost is driven by platform maturity, enterprise requirements, and AI feature scope; timeline by how much of the existing codebase must be refactored first. FISTA does not quote blind: the scoping call returns a specification, an architecture assessment, and a phased estimate.
For existing products, the assessment comes first. Adding multi-region, SSO, or an AI copilot to a codebase with weak tenant boundaries costs more than the feature itself implies. FISTA assesses the codebase, states plainly what must be fixed before the feature is safe, and prices those separately so you can decide the order.
For new products, the trap is building platform capability nobody has asked for yet. FISTA scopes an MVP with the foundations that are genuinely hard to retrofit — tenancy, identity, billing primitives — and defers the rest until a customer requires it.
Send the scope you have, even if it is a paragraph. You get a written brief, an architecture sketch, and a phased estimate before any commitment.
Get a scoped quoteDelivery
How does FISTA deliver an industry software project?
FISTA delivers in four gated phases: a discovery sprint that produces the specification and integration map, an architecture and compliance design that names every control, iterative builds demoed weekly on your environment, and a verified release with runbooks, monitoring, and a handover or a managed operations option.
- 1
Discover and specify
Stakeholder interviews, system inventory, data classification, and a written specification with acceptance criteria and a phased plan.
OutputSpecification, integration map, estimate
- 2
Design for compliance
Architecture, data model, security controls, and the evidence plan for any audit, agreed before the first sprint.
OutputArchitecture decision record, control matrix
- 3
Build and demonstrate
Two-week sprints with automated tests, contract tests on integrations, and a demo on your environment every week.
OutputWorking increments in your repository
- 4
Verify and operate
Load, security, and acceptance testing against the spec; release with runbooks, dashboards, and alerting; optional managed operations.
OutputVerified release, runbooks, SLOs
Why FISTA
Why choose FISTA Solutions for SaaS development?
FISTA builds SaaS with the parts that block enterprise deals and erode margin treated as first-class engineering: provable tenant isolation, procurement-ready documentation, and per-tenant cost attribution on AI features. Work is contracted through a US entity with full IP assignment.
SaaS specifics
- Tenant isolation is enforced at the data-access layer and verified by tenant-scoped tests in CI, so it is demonstrable in a security review.
- Enterprise blockers — SSO, SCIM, audit logs, residency — are planned before the deals that require them.
- AI features carry per-tenant cost attribution and routing, so gross margin is visible in the same dashboard as adoption.
- Codebase assessment happens before feature work, with required remediation priced openly rather than absorbed silently.
How FISTA engineers
- Spec-Driven Development: every deliverable starts as a written specification with acceptance criteria, so scope is testable before it is built.
- AI-native delivery: engineers direct coding agents under review gates and evaluation harnesses, compressing build time without loosening verification.
- Official Anthropic partner, with production experience across Claude, OpenAI, Google, and open-weight models, chosen per workload rather than by default.
- One accountable delivery lead, weekly demos on your environment, and code in your repositories from week one.
What you get as a client
- 150+ projects delivered for 50+ companies across 12+ countries since 2017, with 99.9% verified uptime on systems we operate.
- A US entity (FISTA Solutions Inc., Wilmington, Delaware) for contracting, invoicing, and IP assignment, with an engineering center in Faisalabad, Pakistan for cost-efficient senior capacity.
- US business-hours overlap for standups and reviews; written decision logs so nothing depends on a meeting you missed.
- Flexible engagement: fixed-scope build, embedded forward deployed engineers, or a dedicated team that you can scale month to month.
Clear answers
What buyers in this industry ask first.
Straightforward guidance for evaluating scope, fit, and the next step.
01Can you work on our existing SaaS codebase?
Yes, and most engagements do. FISTA starts with a codebase and architecture assessment, states what must be addressed before the requested feature is safe to build, and delivers inside your repositories, CI, and review process rather than in a parallel track.
02How do you approach multi-tenancy?
Isolation is enforced in the data-access layer rather than by convention, with tenant-scoped tests in CI, per-tenant configuration without code forks, and a documented isolation model you can hand to an enterprise buyer's security team.
03What does enterprise readiness actually require?
Usually SSO and SCIM, granular roles, audit logs, data export and deletion, region options, uptime commitments, and a security documentation pack. FISTA builds those and maintains the documentation so procurement reviews stop resetting your sales cycle.
04How do you keep AI features from destroying gross margin?
By treating cost as a product metric: per-tenant attribution, model routing by task, caching, context discipline, and budgets with alerts. The cost model is built during design, so pricing decisions are informed before launch rather than after the first big bill.
05Can you build our MVP and then hand it over?
Yes. Code, infrastructure-as-code, and documentation live in your repositories from the first sprint, and handover includes runbooks and a working session with your team. Many clients keep FISTA engineers embedded afterwards, but nothing requires it.
06How long does a SaaS MVP take?
A focused MVP typically ships in a few months, depending on integration count and how much platform foundation is genuinely needed at launch. Discovery produces the scope and the phased plan before you commit.
Continue exploring
Related capabilities
Scoped in writing before you commit
Build the SaaS platform your enterprise buyers will approve.
Bring the product, the deal blocker, or the scaling pain. The scoping call returns an architecture assessment, a specification, and a phased estimate.