Some reflections on professional quantum/classical software development
The recent MIT Technology Review report on “Delivering a quantum future”  points out the billion-dollar market potential of quantum computing ($700bn by 2035) and highlights three key points:
1. “While still in its infancy, quantum computing promises problem-solving and computing power that far exceeds today’s most powerful supercomputers.
2. Companies that invest in applications for near-future quantum computers are faced with both the risk of encrypted data leaks and the potential reward of leading the market ahead of competitors.
3. Supporting quantum ambitions means finding a balanced workforce that understands both quantum physics and technology pipelines, expanding the capacity of quantum computers, and taming error rates”.
We agree with these three statements. In fact, we are convinced that we can already see a quantum advantage , or at least a quantum utility , which makes it essential for organizations to embark on this path if they want to remain competitive.
From the software point of view, we were among the first to suggest that quantum computing can bring a new era in software development , which calls for a true quantum software engineering [5, 6]. That is why in these more than five years that we have been dedicated to the subject, we have proposed the Talavera Manifesto , and created the QuantumPath® platform that precisely materializes the principles of the manifesto and allows to carry out a true engineering of the quantum software .
Furthermore, we knew from the beginning, given our experience in professional software, that the key is to take hybrid systems into account when proposing real solutions for the industry, so we created qSOA® (its first version was launched on April 30, 2021), a technology for the dynamic integration of quantum-classical hybrid software systems .
Today, April 14, World Quantum Day, and from the perspective that gives us to be dedicated for more than five years to this area, it seems appropriate to reflect on professional quantum/classical software development. We take into account that this is done with a set of tools, processes, tasks, etc. that make it possible for the magic of hybridizing both IT worlds to be used in a practical and routine way by the industry, namely:
· Apply the best practices of Software Engineering and Quantum Programming to ensure that the software is secure, extensible, high-performance and scalable 
· Design and develop projects in an integrated development environment, as a member of polymath teams of Physicists, Mathematicians, Chemists, Engineers, Programmers, Business, etc. 
· Develop quantum algorithms in a hardware-agnostic way 
· To be able to work with the different technological approaches to quantum computing from unified environments 
· Design and develop quantum gate circuits and annealing formulations that support the complexities of the dynamic management needs of the real world (variables, data, etc.), and the technological reality of the scaling rate expected for current and future QPUs 
· Develop with tools that support software quality control during its life cycle 
· Create dynamically integrated classical/quantum hybrid software solutions and systems 
· Harmoniously integrate hybrid solutions and systems with the classic IT used in the company, organization, etc. 
· Integrate hybrid solutions and systems with third-party quantum products and services 
· Apply BizDevOps as a natural part of the lifecycle of classic/quantum software solutions 
· Implement, by design, software security 
· Develop with tools that facilitate technical tasks, that assist and report on the status of processes and enrich the competencies of quantum/classical software developers 
· Explore results and data using a unified schema without having to worry about the different languages of quantum computers 
· Manage all processes and analyze all stored project telemetry, storing all the data executions into a normalized database space, which gives the user the advantage of analyze it over time and reduce the QPU’s time/energy/cost 
· Store all the executions and their data into a normalized database space, that provides historical data which gave to the user the advantage of analyze it over time and reduce the QPU’s time/energy/cost 
· Manage the risk of the ever-changing reality of developing quantum technologies, having technology alternatives available without disrupting the projects or losing the track record 
All this, and much more, is necessary for the outcome of the development of quantum/classical software solutions and systems to be truly useful for the industry, something unfeasible without specialized knowledge, professional tools, working methods, application of best practices, etc.
We are convinced that for the successful adoption of quantum computing by industry it is not enough to develop good algorithms and excellent experimental use cases. As we have tried to summarize in the list presented above, it is very complex and laborious to make an quantum algorithm or experiment, however simple it may be, work correctly in its hybrid and practical application in the real world.
We are well aware that it is not trivial to take quantum software out of laboratories and experimental developments and apply it successfully in the real world. But, based on our scientific and theoretical experience, and on the practical results that we have embodied in technologies and tools designed to simplify and facilitate the development of quantum software, we are convinced that equipped with robust knowledge, working with strong polymath teams and having the right tools, methods, procedures, sooner rather than later developing industry-ready quantum/classical software professionally will be no more complex than developing high quality classical software professionally.
One of our recurring “quantum dreams” is to create technologies to design professional tools that make it easier for developers to do their job by focusing on the use cases to be developed, being able to leave the underlying technological details to the system (from the model to the results), having a fully automatic life cycle. That is why we work so that the technologies, tools, and services of the QuantumPath® platform increasingly facilitate the professional implementation of quantum/classical software solutions and systems that enable the use of quantum algorithms to solve complex real-world problems through IT deployed in enterprises and organizations.
For us, every day is a Quantum Day. Our goal: to provide the most comprehensive set of software tools, platforms, services, and people to enable the implementation of enterprise solutions that leverage the potential of quantum computers. We are working very hard today to provide the tools of the near future.
 Delivering a quantum future. Innovations require engineering breakthroughs and focus on real computational problems. MIT Technology Review. April 2023 https://www.technologyreview.com/2023/04/07/1069778/delivering-a-quantum-future/
 The Quantum Decade. A playbook for achieving awareness, readiness, and advantage. Third edition. IBM Institute of Business Value. Third edition
 Quantum utility – definition and assessment of a practical quantum advantage. Nils Herrmann, Daanish Arya, Florian Preis, Stefan Prestel, Marcus W. Doherty, Angus Mingare, and Jason C. Pillay. arXiv:2303.02138v1 [quant-ph] 3 Mar 2023.
 Quantum Computing: A New Software Engineering Golden Age. ACM SIGSOFT Software Engineering NotesVolume 45Issue 3July 2020 pp 12-14. https://doi.org/10.1145/3402127.3402131
 Toward a Quantum Software Engineering. M. Piattini, M. Serrano, R. Perez-Castillo, G. Petersen and J. L. Hevia. IT Professional, vol. 23, no. 1, pp. 62-66, 1 Jan.-Feb. 2021, doi: 10.1109/MITP.2020.3019522.
 Quantum Software Engineering. Manuel A. Serrano, Ricardo Pérez-Castillo, Mario Piattini (eds.) Springer, https://link.springer.com/book/10.1007/978-3-031-05324-5
 The Talavera Manifesto for Quantum Software Engineering and Programming. https://ceur-ws.org/Vol-2561/paper0.pdf
 Quantum Software Engineering & QuantumPath®. Guido Peterssen, José Luis Hevia, Mario Piattini. Amazon, 2023, https://www.amazon.es/Quantum-Software-Engineering-QuantumPath%C2%AE-English-ebook/dp/B0BZ5L4L3K
 qSOA®: technology for dynamic integration of quantum-classical hybrid software systems. https://www.quantumpath.es/2022/06/04/qsoa-technology-for-dynamic-integration-of-quantum-classical-hybrid-software-systems/
 Hybrid Systems. José Luis Hevia and Alonso Martín-Toledano García-Mauriño. Chapter 9. Quantum Software Engineering & QuantumPath®. Amazon. 2023
 Quantum Software Development with QuantumPath®. Guido Peterssen, Jose Luis Hevia, and Mario Piattini. Chapter13. Quantum Software Engineering. Springer.
 QuantumPath: A quantum software development platform. Jose Luis Hevia, Guido Peterssen, Mario Piattini. Softw. Pract. Exp. 52(6): 1517-1530 (2022). https://onlinelibrary.wiley.com/doi/full/10.1002/spe.3064
 Technology risk management in quantum systems with QuantumPath®. https://www.quantumpath.es/qpath-risk-management-advantage/