How to Make an App Like Smartsheet

Smartsheet turned the humble spreadsheet into a full-blown work management platform, and in doing so it built a business serving millions of users across hundreds of thousands of organizations. If you've ever looked at it and thought, "I could build something better for my niche," you're not wrong — but you should know exactly what you're walking into.

This guide breaks down what Smartsheet actually is under the hood, the features you need for a credible first release, the architecture decisions that will make or break you, and a realistic view of cost and timeline.

What Smartsheet Actually Is

It helps to be precise about the product category before you start writing code. Smartsheet sits at the intersection of three things:

1. A spreadsheet interface — rows, columns, formulas, cell-level formatting. Familiar to anyone who has used Excel.
2. A project management engine — dependencies, critical paths, Gantt charts, resource allocation, baselines.
3. A collaboration and automation layer — comments, attachments, approval workflows, alerts, forms, and integrations with the rest of the business software stack.

The magic isn't any one of those. It's that a non-technical operations manager can build something that behaves like a custom internal application without ever talking to IT. That's the real product. Keep it in mind, because it should drive every design decision you make.

Step 1: Pick a Wedge Before You Pick a Tech Stack

Competing with Smartsheet head-on as a general-purpose work management tool is a brutal fight. Airtable, Monday.com, Asana, ClickUp, Notion, and Wrike are all in that ring, and they're all well funded.

The apps that succeed here start narrow and vertical. Some directions that work:

• Construction and field services — punch lists, submittals, RFIs, daily logs, photo documentation tied to rows.
• Clinical research or healthcare ops — audit trails, HIPAA compliance, protocol tracking.
• Marketing and creative production — asset review cycles, campaign calendars, proofing.
• Manufacturing and supply chain — BOM tracking, supplier scorecards, inbound logistics.
• Professional services — resource forecasting, utilization, billable project tracking.

A vertical wedge lets you ship a smaller feature set that feels more complete than Smartsheet for that audience, because you can pre-build the templates, terminology, compliance posture, and integrations they already need.

Step 2: Define the MVP Feature Set

Resist the urge to clone everything. Here's a defensible minimum.

The Grid

This is the hardest and most important part. Users expect:

• Add, delete, reorder, resize, freeze, and hide columns
• Typed columns: text, number, date, dropdown (single/multi), checkbox, contact, currency, auto-number, formula
• Row hierarchy — indent and outdent to create parent/child relationships with roll-up calculations
• Inline editing with keyboard navigation (tab, arrow keys, enter-to-commit)
• Copy/paste from Excel and Google Sheets, including multi-cell ranges
• Conditional formatting rules
• Sorting, multi-condition filtering, and grouping
• Cell-level comments and attachments

Alternate Views

Same data, different lenses. At minimum:

• Gantt with drag-to-adjust bars, dependency lines, and a critical path
• Kanban/card view grouped by a chosen column
• Calendar view driven by start/end date columns
• Dashboard/report view with charts, metric widgets, and cross-sheet roll-ups

Forms

A form builder that generates a public or internal intake form which writes new rows into a sheet. This is one of Smartsheet's highest-value, lowest-complexity features — prioritize it.

Automation

A trigger-condition-action rule builder:

• Triggers: row added, cell changed, date reached, recurring schedule
• Conditions: field comparisons with AND/OR logic
• Actions: send alert, request approval, assign user, move/copy row, change cell value, call a webhook

Collaboration and Permissions

• Workspace → folder → sheet hierarchy
• Role-based sharing: owner, admin, editor, commenter, viewer
• Row-level and column-level permissions (this is a genuine enterprise requirement)
• Activity log and cell history
• @mention notifications, email digests

Integrations

Ship with a handful, not thirty. Google Workspace, Microsoft 365/Teams, Slack, and a Zapier or Make connector will cover most early customers. Then add the two or three vertical-specific systems your wedge audience lives in.

Step 3: Architecture and Technical Decisions

The Data Model Problem

You're building a product where users define their own schemas at runtime. There are three common approaches:

Approach	How it works	Trade-off
EAV (entity-attribute-value)	One row per cell value	Maximum flexibility, painful queries, hard to index
JSONB documents	Row stored as a JSON blob with a separate schema definition	Good balance; PostgreSQL JSONB with GIN indexes performs well
Dynamic physical tables	Create a real table per user sheet	Fast reads, but migrations and connection/table limits become a nightmare at scale

Most modern teams land on PostgreSQL with JSONB row payloads plus a normalized column-definition table. You get relational integrity for metadata, flexibility for cell data, and a clear upgrade path. Add a column-store or OLAP layer (ClickHouse, DuckDB, BigQuery) later when reporting across thousands of sheets gets slow.

Real-Time Collaboration

Two people editing the same sheet is table stakes. Your options:

• Operational Transformation (OT) — battle-tested but complex to implement correctly
• CRDTs — libraries like Yjs or Automerge handle conflict resolution for you and work well offline
• Last-write-wins with cell-level locking — much simpler, acceptable for many B2B use cases

For a first version, cell-level optimistic locking over WebSockets with a clear "someone else is editing this cell" indicator is often enough. Don't build a Google-Docs-grade CRDT engine before you've validated demand.

The Formula Engine

You'll need a parser, an evaluator, and a dependency graph. Key requirements:

• Tokenize and parse formulas into an AST
• Build a directed acyclic graph of cell dependencies and detect cycles
• Recalculate only affected cells (topological order), not the whole sheet
• Evaluate server-side for consistency, optionally client-side for instant feedback
• Support cross-sheet references eventually — plan the reference format now

Libraries like HyperFormula or Formula.js can accelerate this considerably. Writing one from scratch is a multi-month project on its own.

Frontend

The grid must handle tens of thousands of rows without choking. That means:

• Virtualized rendering — only paint visible rows and columns (TanStack Virtual, react-window)
• Canvas-based rendering for very large datasets, which is what the fastest grids use
• Consider a commercial grid (AG Grid Enterprise, Handsontable, Glide Data Grid) to skip six months of work — then evaluate whether licensing costs make sense long-term

React or Vue with TypeScript, a state manager suited to normalized data, and strict attention to re-render boundaries.

Backend

• API: REST for CRUD plus WebSockets for live updates; GraphQL if clients need flexible field selection
• Language/runtime: Node.js/TypeScript, Go, or Python — Go shines for the sync and calculation services
• Queue: Redis or SQS for automation execution, notifications, imports, and exports
• Search: Elasticsearch or Postgres full-text for cross-sheet search
• Storage: S3-compatible object storage for attachments, with signed URLs
• Infra: Containers on Kubernetes or a managed platform, with per-tenant data isolation strategy decided upfront

Mobile

Smartsheet's mobile apps are deliberately scoped down: view data, update rows, submit forms, respond to approvals, capture photos. Nobody wants to build a Gantt chart on a phone. React Native or Flutter is usually the right call — one codebase, offline queue, camera and file access, push notifications.

Step 4: Security and Compliance

Enterprise buyers will send you a security questionnaire before they send you a contract. Plan for:

• SSO via SAML 2.0 and OIDC, plus SCIM user provisioning
• Granular RBAC, enforced at the API layer and not just the UI
• Encryption in transit and at rest; consider customer-managed keys for larger deals
• Immutable audit logs of every data and permission change
• SOC 2 Type II as the baseline certification; HIPAA, GDPR, or FedRAMP depending on your vertical
• Data residency options if you're selling into the EU

Retrofitting this is far more expensive than designing for it. Build the audit log and permission model on day one.

Step 5: Scale and Performance Targets

Set explicit budgets early, then test against them:

• Load a 20,000-row sheet in under two seconds
• Reflect a cell edit to other collaborators in under 300ms
• Recalculate a dependency chain of 5,000 cells in under one second
• Import a 50MB Excel file without timing out
• Render a dashboard pulling from 20 sheets in under three seconds

Use pagination and windowed fetching on the API, aggressive caching of column definitions and permissions, read replicas for reporting, and a separate worker fleet for automations so a customer's runaway workflow rule doesn't degrade everyone's grid performance.

Step 6: Where AI Fits

This is the most obvious place to differentiate, because Smartsheet's own AI features are still relatively new. Practical, valuable additions:

• Natural language sheet creation — "build me a sheet to track vendor onboarding with approval steps"
• Formula generation and explanation from plain English
• Automated data extraction from uploaded PDFs, invoices, or emails directly into rows
• Summarization of long comment threads and project status
• Predictive flags — schedule slip risk based on historical completion patterns
• Conversational querying of data across sheets

Keep AI features scoped and verifiable. Users forgive a wrong suggestion; they don't forgive silently corrupted data.

Step 7: Monetization

The established model in this space:

• Per-user seat pricing in tiers (Pro / Business / Enterprise), differentiated by automation volume, integrations, admin controls, and support SLAs
• Free viewer or commenter seats — critical for adoption, since stakeholders who only read shouldn't cost money
• Usage-based add-ons for automation runs, API calls, AI credits, or storage
• Enterprise annual contracts with SSO, audit, and dedicated support
• Template marketplace or vertical solution packs as expansion revenue

Free viewers are a growth mechanism, not a concession. Smartsheet's licensing model is one reason it spread virally inside large organizations.

Cost and Timeline

Rough ranges for a competent team building a production-grade vertical alternative:

Phase	Scope	Timeline	Indicative cost
Discovery and design	Research, UX, prototypes, architecture	4–6 weeks	$15k–$35k
MVP	Grid, one alternate view, forms, sharing, basic automation	4–6 months	$90k–$200k
Full v1	Gantt, dashboards, integrations, mobile, SSO	6–10 months	$200k–$450k
Enterprise readiness	SOC 2, advanced permissions, scale work	3–5 months	$60k–$150k

Costs vary widely by team location and seniority. The biggest swing factors are whether you license a commercial grid component, how sophisticated your formula engine needs to be, and how early you chase enterprise compliance.

Ongoing costs are real too: infrastructure, third-party licenses, security audits, and a support function that can answer "why did my formula break?"

Common Mistakes to Avoid

• Building the grid last. It's the core of the product and the hardest part. Prototype it in week one.
• Cloning the feature list instead of the value. Smartsheet has fifteen years of accumulated features. You need the ten percent that matters to your wedge.
• Ignoring Excel import/export. Every prospect's data lives in spreadsheets today. Frictionless import is your onboarding funnel.
• Underestimating permissions. Row- and column-level access control touches every query in your system. Design it before you write the first endpoint.
• Skipping the audit log. Enterprise deals die on this.
• Neglecting templates. Nobody wants to start from a blank grid. Ship twenty excellent, opinionated templates for your vertical.

Getting Started

The path that consistently works: pick one vertical, interview twenty people who currently duct-tape Excel and email together to do the job, build the grid plus forms plus one automation type for exactly their workflow, and get it into production with five paying teams before you build a Gantt chart.

Smartsheet won by making powerful software feel like a spreadsheet. You'll win the same way — by making it feel like a tool built specifically for your customers' work, not a blank canvas they have to figure out.

Have a project in mind? Contact Sodio Technologies to discuss your requirements and explore the right technology solution for your business.